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1
LEE, YUAN-HAUN, TZONG-FU KUO, BOR-YANN CHEN, YI-KAI FENG, YU REN WEN, WU-CHING LIN, and F. H. LIN. "TOXICITY ASSESSMENT OF MONTMORILLONITE AS A DRUG CARRIER FOR PHARMACEUTICAL APPLICATIONS: YEAST AND RATS MODEL." Biomedical Engineering: Applications, Basis and Communications 17, no. 02 (April 25, 2005): 72–78. http://dx.doi.org/10.4015/s1016237205000111.
Повний текст джерелаАнотація:
Our previous study indicated that montmorillonite (MMT for short) was pharmaceutically feasible to be used as a carrier of an anticancer drug 5-FU. Emphasis of this study is thus placed on the toxicity of MMT to address whether it is clinically safe for practical use. Hematological data of rats model showed that the rats administered with oral MMT had significant increases in hemoglobin (Hb) concentration, Hamatocrit and RBC count than those of oral PBS buffer (p<0.05). However, MCV, MCH, MCHC, WBC Count and WBC were not statistically significant different between experimental and control group (p>0.05). Hematological analysis for intravenous injection also showed no statistically significant differences between experimental and control group (p>0.05). Biochemical analysis pointed out that compared to oral PBS there was not only a significant decrease of sodium (Na+) and chloride (Cl−) ion (p<0.05) in plasma for oral MMT, but also an extremely significant decrease in the plasma calcium (Ca2+)(p<0.01). On the other hand, after intravenous injection of MMT compared to control group, a significant increase (p<0.05) in ALT (SGPT), and an extremely significant decease (p<0.01) in plasma potassium (K+) were observed. It is deserved to mention here that histochemical examinations were all normal, suggesting that montmorillonite may be considered non-toxic. Regarding histopathological sections of rats, there were all in normal ranges irrespective of experimental or control group. For bacterial model, a generally considered safe and non-pathological microorganism Saccharomyces cerevisiae was used as the model yeast to be administrated with various extracellular doses of MMT, montmorillonite-K6Fe(CN)3 (MMTK), or montmorillonite-K6Fe(CN)3-sodium alginate (MMTK-SA) for toxicological assessments. Dose-response analysis indicated that the toxicity ranking as Lannate ≫ MMTK > MMTK-SA ≫ MMT-SA > MMT according to EC0 or EC50 line. These all suggested that MMT alone is much less toxic than Lannate and potassium hexacyanoferrate(III). Apparently, it was concluded that MMT alone could be considered non-toxic to S. cerevisiae and Wistar rat for myriads of applications.
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Bishop, Kevin P., Steve Constable, Nabil F. Faruk, and Pierre-Nicholas Roy. "OpenMM accelerated MMTK." Computer Physics Communications 191 (June 2015): 203–8. http://dx.doi.org/10.1016/j.cpc.2015.01.025.
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Wong, Stephanie Y. Y., Pierre-Nicholas Roy, and Alex Brown. "Ab initio electronic structure and direct dynamics simulations of CH3OCl." Canadian Journal of Chemistry 87, no. 7 (July 2009): 1022–29. http://dx.doi.org/10.1139/v09-073.
Повний текст джерелаАнотація:
The ground (X1A′) and two lowest lying excited singlet states (11A″ and 21A′) of methyl hypochlorite have been examined using ab initio electronic structure techniques to validate computationally efficient methods, upon which direct dynamics can be based, versus high-level ones, for which direct dynamics would be intractable. Ground-state equilibrium geometries and vibrational frequencies determined using density functional theory (DFT) with the 6-31G(d) basis set are tested against coupled-cluster theory (CCSD(T)) results from the literature. Vertical excitation energies and transition dipole moments calculated at the complete active space self-consistent field CASSCF/6-31+G(d) level of theory are benchmarked against multireference configuration interaction (MRCI) results with the aug-cc-pVXZ (X = D, T, Q) family of basis sets. The excited-state gradients that will govern the classical dynamics are compared for CASSCF/6-31+G(d) versus MRCI/aug-cc-pVXZ (X = D, T). To carry out the ab initio molecular dynamics (AIMD), existing electronic structure codes have been interfaced with the molecular modelling toolkit (MMTK), an open-source program library for molecular simulation applications. We use two examples to demonstrate the use of direct dynamics in MMTK: a canonical ground-state trajectory to sample positions and momenta, and an excited-state microcanonical trajectory based on CASSCF. The work presented here forms the basis for future study of the photodissociation of CH3OCl. As well, the implementation of AIMD within MMTK provides a useful tool for examining a variety of other research problems.
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BACHER, Walter, and Volker SAILE. "MMTK LIGA AND AMANDA TECHNOLOGIES FOR THE FABRICATION OF ADVANCED MICRO-DEVICES." Proceedings of JSME-IIP/ASME-ISPS Joint Conference on Micromechatronics for Information and Precision Equipment : IIP/ISPS joint MIPE 2003 (2003): 133–37. http://dx.doi.org/10.1299/jsmemipe.2003.133.
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Li, Liangtao, Sophie Bertram, Jerry Kaplan, Xuan Jia, and Diane M. Ward. "The mitochondrial iron exporter genes MMT1 and MMT2 in yeast are transcriptionally regulated by Aft1 and Yap1." Journal of Biological Chemistry 295, no. 6 (January 2, 2020): 1716–26. http://dx.doi.org/10.1074/jbc.ra119.011154.
Повний текст джерелаАнотація:
Budding yeast (Saccharomyces cerevisiae) responds to low cytosolic iron by up-regulating the expression of iron import genes; iron import can reflect iron transport into the cytosol or mitochondria. Mmt1 and Mmt2 are nuclearly encoded mitochondrial proteins that export iron from the mitochondria into the cytosol. Here we report that MMT1 and MMT2 expression is transcriptionally regulated by two pathways: the low-iron-sensing transcription factor Aft1 and the oxidant-sensing transcription factor Yap1. We determined that MMT1 and MMT2 expression is increased under low-iron conditions and decreased when mitochondrial iron import is increased through overexpression of the high-affinity mitochondrial iron importer Mrs3. Moreover, loss of iron-sulfur cluster synthesis induced expression of MMT1 and MMT2. We show that exposure to the oxidant H2O2 induced MMT1 expression but not MMT2 expression and identified the transcription factor Yap1 as being involved in oxidant-mediated MMT1 expression. We defined Aft1- and Yap1-dependent transcriptional sites in the MMT1 promoter that are necessary for low-iron- or oxidant-mediated MMT1 expression. We also found that the MMT2 promoter contains domains that are important for regulating its expression under low-iron conditions, including an upstream region that appears to partially repress expression under low-iron conditions. Our findings reveal that MMT1 and MMT2 are induced under low-iron conditions and that the low-iron regulator Aft1 is required for this induction. We further uncover an Aft1-binding site in the MMT1 promoter sufficient for inducing MMT1 transcription and identify an MMT2 promoter region required for low iron induction.
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Yuan, Stephen Hsien-Chi, Shih-Chieh Chang, Yenlin Huang, and Hao-Ping Liu. "Serum Level of Tumor-Overexpressed AGR2 Is Significantly Associated with Unfavorable Prognosis of Canine Malignant Mammary Tumors." Animals 11, no. 10 (October 9, 2021): 2923. http://dx.doi.org/10.3390/ani11102923.
Повний текст джерелаАнотація:
Canine malignant mammary tumors (MMTs) are prevalent malignancy in intact female dogs with a high incidence of metastasis and recurrence. A current lack of easily accessible tumor biomarkers hinders a timely assessment of the disease outcome. We previously identified anterior gradient protein 2 (AGR2) with higher protein abundance in canine MMT tissues compared with normal counterparts. AGR2 is an endoplasmic reticulum-resident protein disulfide isomerase involved in the regulation of protein processing and also exists extracellularly via secretion to exert pro-oncogenic functions. In the present study, we validated overexpression of AGR2 in canine MMT tissues from 45 dogs using immunohistochemistry and immunoblotting, and assessed serum AGR2 levels in 81 dogs with MMTs and 21 benign cases using a competitive enzyme-linked immunosorbent assay (ELISA). Our data revealed that serum eAGR2 levels are significantly correlated with MMT progression (p = 0.0007) and remote tumor metastasis (p = 0.002). Moreover, elevated levels of serum eAGR2 are associated with an unfavorable overall survival of MMT dogs in later stage (p = 0.0158). Area under the time-dependent ROC curve (AUC) of serum eAGR2 level as a prognostic indicator was 0.839. Collectively, this study uncovered that serum eAGR2 level is significantly associated with an adverse outcome of MMT dogs and holds a predictive potential in MMT prognosis.
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Hartung, Svenja, Elfi K. Schlohsarczyk, Alexandra Jost, Marlene Sickinger, and Kernt Köhler. "Benign mixed Müllerian (duct) vaginal tumor in a 12-y-old goat." Journal of Veterinary Diagnostic Investigation 34, no. 2 (January 10, 2022): 298–301. http://dx.doi.org/10.1177/10406387211069370.
Повний текст джерелаАнотація:
In human and veterinary medicine, mixed Müllerian tumors (MMTs) are rarely diagnosed neoplasms of the tubular female genital tract. Although there are case reports of malignant MMTs in various species, benign MMTs have only been described once in a macaque. Here we present a case of benign MMT in a 12-y-old goat, and review the literature on uterine, cervical, and vaginal neoplasia in goats. The doe was presented with vaginal discharge and was euthanized because of the high suspicion of intraabdominal neoplasia. On gross examination, an ulcerated vaginal mass was identified. Histologically, 2 distinct cell populations were present: smooth muscle cells that were well differentiated and positive for alpha–smooth muscle actin, and ciliated columnar epithelial cells that lined ductal structures and had no signs of malignancy. These findings led to the diagnosis of neoplasia of Müllerian origin. Benign MMT should be considered as a differential diagnosis for uterine and vaginal neoplasms in goats.
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Shi, Chen Jie, Xiao Yan Li, Xia Wang, Yuan Wen Wang, Zhen Lu, and Ling Ling Xie. "The Compatibility Research of the Organic Montmorillonites with SEBS." Advanced Materials Research 1044-1045 (October 2014): 128–32. http://dx.doi.org/10.4028/www.scientific.net/amr.1044-1045.128.
Повний текст джерелаАнотація:
To improve the compatibility of montmorillonite (MMT) with polymer. A kind of organic intercalation agent was applied in the intercalating organic modification of montmorillonite (OMMT) through ion exchange method, and a kind of silane coupling agent was further used to do the organic treatment. The SEBS/OMMTs composites were also prepared by melt blending. Structure and characterization of the modified MMTs were investigated by Fourier Transform infrared (FT-IR), wide angle X-ray diffraction (WAXRD), and the thermal stability were characterized by Thermogravimetric analysis (TGA). The dispersion status of MMTs were evaluated by scanning electron microscope (SEM) and the composites were tested by universal material testing machine. The FTIR results initial displayed that OMMTs had the absorption peak of organic functional groups. The XRD results showed that compared to Na+-MMT(1.47 nm), the layer spacing of H-OMMT increased to 3.27 nm, the above two results showed the organic modification of MMT had succeed. The results of TGA showed that OMMTs had a weight loss of organics. The SEM demonstrated that H-OMMT had the best dispersion status in SEBS matrix, and Na+-MMT was the worst.
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Ronkay, Ferenc, Béla Molnár, Ferenc Szalay, Dóra Nagy, Brigitta Bodzay, István E. Sajó, and Katalin Bocz. "Development of Flame-Retarded Nanocomposites from Recycled PET Bottles for the Electronics Industry." Polymers 11, no. 2 (February 1, 2019): 233. http://dx.doi.org/10.3390/polym11020233.
Повний текст джерелаАнотація:
Recycled polyethylene-terephthalate (rPET) nanocomposites of reduced flammability were prepared by combining aluminum-alkylphosphinate (AlPi) flame retardant (FR) and natural montmorillonite (MMT), in order to demonstrate that durable, technical products can be produced from recycled materials. During the development of the material, by varying the FR content, the ratio and the type of MMTs, rheological, morphological, mechanical and flammability properties of the nanocomposites were comprehensively investigated. Related to the differences between the dispersion and nucleation effect of MMT and organo-modified MMT (oMMT) in rPET matrix, analyzed by Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and Differential Scanning Calorimetry (DSC), mechanical properties of the nanocomposites changed differently. The flexural strength and modulus were increased more significantly by adding untreated MMT than by the oMMT, however the impact strength was decreased by both types of nanofillers. The use of different type of MMTs resulted in contradictory flammability test result; time-to-ignition (TTI) during cone calorimeter tests decreased when oMMT was added to the rPET, however MMT addition resulted in an increase of the TTI also when combined with 4% FR. The limiting oxygen index (LOI) of the oMMT containing composites decreased independently from the FR content, however, the MMT increased it noticeably. V0 classification according to the UL-94 standard was achieved with as low as 4% FR and 1% MMT content. The applicability of the upgraded recycled material was proved by a pilot experiment, where large-scale electronic parts were produced by injection molding and characterized with respect to the commercially available counterparts.
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Stodolak-Zych, Ewa, Roksana Kurpanik, Ewa Dzierzkowska, Marcin Gajek, Łukasz Zych, Karol Gryń, and Alicja Rapacz-Kmita. "Effects of Montmorillonite and Gentamicin Addition on the Properties of Electrospun Polycaprolactone Fibers." Materials 14, no. 22 (November 16, 2021): 6905. http://dx.doi.org/10.3390/ma14226905.
Повний текст джерелаАнотація:
Electrospinning was used to obtain multifunctional fibrous composite materials with a matrix of poly-ɛ-caprolactone (PCL) and 2 wt.% addition of a nanofiller: montmorillonite (MMT), montmorillonite intercalated with gentamicin sulphate (MMTG) or gentamicin sulphate (G). In the first stage, the aluminosilicate gallery was modified by introducing gentamicin sulfate into it, and the effectiveness of the intercalation process was confirmed on the basis of changes in the clay particle size from 0.5 µm (for MMT) to 0.8 µm (for MMTG), an increase in the interplanar distance d001 from 12.3 Å (for MMT) to 13.9 Å (for MMTG) and altered clay grain morphology. In the second part of the experiment, the electrospinning process was carried out in which the polymer nonwovens with and without the modifier were prepared directly from dichloromethane (DCM) and N,N-dimethylformamide (DMF). The nanocomposite fibrous membranes containing montmorillonite were prepared from the same polymer solution but after homogenization with the modifier (13 wt.%). The degree of dispersion of the modifier was evaluated by average microarray analysis from observed area (EDS), which was also used to determine the intercalation of montmorillonite with gentamicin sulfate. An increase in the size of the fibers was found for the materials with the presence of the modifier, with the largest diameters measured for PCL_MMT (625 nm), and the smaller ones for PCL_MMTG (578 nm) and PCL_G (512 nm). The dispersion of MMT and MMTG in the PCL fibers was also confirmed by indirect studies such as change in mechanical properties of the nonwovens membrane, where the neat PCL nonwoven was used as a reference material. The addition of the modifier reduced the contact angle of PCL nonwovens (from 120° for PCL to 96° for PCL_G and 98° for PCL_MMTG). An approximately 10% increase in tensile strength of the nonwoven fabric with the addition of MMT compared to the neat PCL nonwoven fabric was also observed. The results of microbiological tests showed antibacterial activity of all obtained materials; however, the inhibition zones were the highest for the materials containing gentamicin sulphate, and the release time of the active substance was significantly extended for the materials with the addition of montmorillonite containing the antibiotic. The results clearly show that the electrospinning technique can be effectively used to obtain nanobiocomposite fibers with the addition of nonintercalated and intercalated montmorillonite with improved strength and increased stiffness compared to materials made only of the polymer fibers, provided that a high filler dispersion in the spinning solution is obtained.
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Hagiwara, Masaya, Miyako Niimi, Tomohiro Kawahara, Yoko Yamanishi, Hayao Nakanishi, and Fumihito Arai. "On-Chip Particle Sorting into Multiple Channels by Magnetically Driven Microtools." Journal of Robotics and Mechatronics 23, no. 3 (June 20, 2011): 370–77. http://dx.doi.org/10.20965/jrm.2011.p0370.
Повний текст джерелаАнотація:
This paper presents a new type of sorting system by magnetic microtools (MMT) separating particles into multiple channels. Two nickel-based MMTs are activated by commercially available permanent magnets below the biochip to lead particles to certain channels via fluid force. The horizontally assembled permanent magnet drive we developed shows that the MMT positioning accuracy had been improved 5 times in 2 degrees of freedom. The channel and the MMT shape are determined based on FEM analysis to ensure that particles flow smoothly. We have successfully achieved to sort 100 µm diameter microbeads into 7 branched channels. The noncontact drive and disposable chip provide a less invasive environment for the cell with low cost.
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Zhao, Man, Wenyi Wang, Lei Wei, Peng Chen, Fengjie Yuan, Zhao Wang, and Xiangxian Ying. "Molecular evolution and expression divergence of three key Met biosynthetic genes in plants: CGS, HMT and MMT." PeerJ 6 (December 4, 2018): e6023. http://dx.doi.org/10.7717/peerj.6023.
Повний текст джерелаАнотація:
Methionine (Met) is an essential sulfur-containing amino acid in animals. Cereal and legume crops with limiting levels of Met represent the major food and feed sources for animals. In plants, cystathionine gamma-synthase (CGS), methionine methyltransferase (MMT) and homocysteine methyltransferase (HMT) are committing enzymes synergistically synthesizing Met through the aspartate (Asp) family pathway and the S-methylmethionine (SMM) cycle. The biological functions of CGS, MMT and HMT genes have been respectively studied, whereas their evolution patterns and their contribution to the evolution of Met biosynthetic pathway in plants are unknown. In the present study, to reveal their evolution patterns and contribution, the evolutionary relationship of CGS, MMT and HMT gene families were reconstructed. The results showed that MMTs began in the ancestor of the land plants and kept conserved during evolution, while the CGSs and HMTs had diverged. The CGS genes were divided into two branches in the angiosperms, Class 1 and Class 2, of which Class 2 only contained the grasses. However, the HMT genes diverged into Class 1 and Class 2 in all of the seed plants. Further, the gene structure analysis revealed that the CGSs, MMTs and HMTs were relatively conserved except for the CGSs in Class 2. According to the expression of CGS, HMT and MMT genes in soybeans, as well as in the database of soybean, rice and Arabidopsis, the expression patterns of the MMTs were shown to be consistently higher in leaves than in seeds. However, the expression of CGSs and HMTs had diverged, either expressed higher in leaves or seeds, or showing fluctuated expression. Additionally, the functions of HMT genes had diverged into the repair of S-adenosylmethionine and SMM catabolism during the evolution. The results indicated that the CGS and HMT genes have experienced partial subfunctionalization. Finally, given the evolution and expression of the CGS, HMT and MMT gene families, we built the evolutionary model of the Met biosynthetic pathways in plants. The model proposed that the Asp family pathway existed in all the plant lineages, while the SMM cycle began in the ancestor of land plants and then began to diverge in the ancestor of seed plants. The model suggested that the evolution of Met biosynthetic pathway is basically consistent with that of plants, which might be vital to the growth and development of different botanical lineages during evolution.
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Syaimak, Abdul Shukor. "Machining a Micro-Scale Structure Using an in-House Developed Miniature Machine Tool." Advanced Materials Research 418-420 (December 2011): 1502–6. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.1502.
Повний текст джерелаАнотація:
Custom-built Miniature Machine Tools (MMTs) are now becoming more popular with the demand for reduced energy consumption and workshop floor when machining small/medium batch size micro-components. This paper investigates the capability of a custom-built 4-axis MMT through machining a micro-component demonstrator. The experiments have been carried out in Titanium Alloyed (TiAL6V4) using 0.6mm solid carbide flat end mill cutters. From here, the surface quality and geometrical accuracy of the machined testpiece are evaluated and analysed. The investigation has shown that acceptable geometrical accuracies and surface quality of the machined micro-demonstrator can be achieved using the in-house developed MMT. These results show that the use of the custom-made MMT does not hinder the micro-milling process to produce a good and satisfactory surface quality and acceptable geometrical accuracy.
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Lee, Sang Won, Rhett Mayor, and Jun Ni. "Dynamic Analysis of a Mesoscale Machine Tool." Journal of Manufacturing Science and Engineering 128, no. 1 (June 21, 2005): 194–203. http://dx.doi.org/10.1115/1.2123007.
Повний текст джерелаАнотація:
Miniaturized machine tools, referred to as mesoscale machine tools (mMTs) henceforth, have been proposed as a way to manufacture micro/mesoscale mechanical components. A thorough study of the dynamic behavior of the mMT is required for the successful development of its machine structure. This paper demonstrates the development of an mMT, the performance evaluation of its mesoscale milling process, and the characterization of its dynamic behavior. The mMT is developed by using an air turbine spindle and three piezoelectric linear stages, and its volumetric size is 150×70×140mm. A series of micro/mesoscale milling experiments are conducted, and the performances in the developed mMT testbed are evaluated. The dynamic characteristics of the mMT can be different from those of conventional machine tools because the mMT is a miniaturized structure and comprises different machine components. Therefore, the effect of the miniaturization of a structure on the change of its dynamic behavior, called scaling law of the structural dynamics, is studied numerically and experimentally. The dynamic characteristics of the developed mMT that are estimated from the scaling law of the structural dynamics are much different from those obtained from an experimental modal analysis, and the flexible joints of the developed mMT are mainly responsible for this significant difference. Therefore, the joint dynamics of the mMT are studied by introducing an equivalent lumped parameter model, thus enabling simple identification of the joint dynamics and the effective modification of its critical joints to enhance a machining performance.
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Koshevaya, A., G. Soldatova, and S. Chigarkova. "Productivity of tasks performance in children and adolescents with different level of media multitasking." European Psychiatry 64, S1 (April 2021): S207. http://dx.doi.org/10.1192/j.eurpsy.2021.551.
Повний текст джерелаАнотація:
IntroductionMedia multitasking (MMT) begins to play an increasingly important role in terms of the digitalization of everyday life. At the same time, the effect of MMT on efficiency is still poorly highlighted, especially among the younger generation (May, Elder, 2018; Patterson, 2017; Peifer, Zipp, 2019).ObjectivesThe aim is to identify types of MMT in children and compare them by productivity and time of task performance.Methods Quasi-experimental research, which included the performance of tasks on a computer and a smartphone, was conducted among children in three groups aged 7-10 years, 11-13 years, 14-16 years (N=154).ResultsBased on a number of criteria, several types of behavior are identified in the MMT environment: two subgroups of “single-taskers” (23%), “light” (19%), “medium” (54%) and “heavy” (4%) MMT. Comparative analysis (p=0.027) reveals high scores for proper task performance of the subgroup “single-taskers1”, as well as “heavy” and “light” MMT. The other subgroup “single-taskers2” and “medium” MMT show, on the contrary, low productivity results. MMT groups also differ in terms of task performance time (p=0.006). The “light” and “heavy” MMT cope the fastest. The second place by the speed of task performance is held by “medium” MMTs and “single-taskers1”, and the slowest are “single-taskers2”.Conclusions The results show that both linear and nonlinear behavioral strategies can lead to a certain level of performance. Most children try to operate in the MMT mode and it is becoming the dominant and ubiquitous modus vivendi for the younger generation. The reported study was funded by RFBR, project No. 19-29-14181.Conflict of interestThe reported study was funded by RFBR, project No. 19-29-14181.
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Zheng, Qiang, Bo Xu, Yihu Song, Hongmei Yang, and Yi Pan. "Interlayer structure of organically modified montmorillonites: Effect of surfactant loading." Journal of Materials Research 20, no. 2 (February 2005): 357–63. http://dx.doi.org/10.1557/jmr.2005.0063.
Повний текст джерелаАнотація:
The surfactant cetyltrimethylammonium ion (CTA+) was confined within the galleries of montmorillonite (MMT) to obtain a series of organo-montmorillonites (C16-MMTs) through an ion-exchange intercalation reaction. The C16-MMT formed a single precipitate layer when CTA+ loading was 18.3 wt% but stratified at high loadings. The conformational disorder increased with increasing CTA+ loading. The upper precipitate was characterized by a larger gallery height and a higher surfactant loading in comparison with lower precipitate. The confined methylene chains adopted a lateral monolayer with a small percentage of conformation freedoms at CTA+ loading of 18.3 wt%. The intercalated methylene chains were arranged either in a lateral monolayer or in a tilted interdigitated bilayer at CTA+ loading of 24.7 wt% while in either a tilted interdigitated bilayer or a lateral bilayer at high CTA+ loadings. The different arrangements of methylene chains intercalated in the MMT galleries are believed to be the reason for the stratification.
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DİRİLMİŞ, Mehmet, and Muhammed GÖKSOY. "Atık Alüminyum Metal Matrisli Kompozit Malzemelerde Al2O3 Takviye Oranının Isı İletim Katsayısına Etkisinin İncelenmesi." Harran Üniversitesi Mühendislik Dergisi 7, no. 3 (December 30, 2022): 173–80. http://dx.doi.org/10.46578/humder.1150924.
Повний текст джерелаАнотація:
Bu çalışmada, matris malzemesi olarak geri dönüşümden faydalanılarak atık içecek kutuları kullanılmıştır. Üretimi yapılan metal matrisli kompozit malzemenin (MMK) içerisine takviye elemanı olarak Al2O3 nano partikül kullanılmıştır. Metal matrisli nanopartikül takviyeli kompozit (MMNK) üretiminde Al2O3 takviye oranı ağırlıkça %0,5, %1, %1,5 belirlenmiş olup, karıştırmalı döküm yöntemi kullanılarak deney numuneleri hazırlanmıştır. Takviye oranındaki değişimlerin kompozit malzemenin termal özelliklerine etkileri deneysel olarak incelenmiştir. Alüminyum matris içerisindeki Al2O3 takviye oranlarının artmasıyla kompozit malzemenin termal iletkenlik değerlerinin orantılı olarak azaldığı görülmüştür.
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Julián R. Camargo L et al.,, Julián R. Camargo L. et al ,. "Algorithm For Simulation of Blocking Probability in Queues of Type MM1K and MMKK for Data Servers." International Journal of Mechanical and Production Engineering Research and Development 10, no. 3 (2020): 13405–14. http://dx.doi.org/10.24247/ijmperdjun20201277.
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Li, Liangtao, Ren Miao, Xuan Jia, Diane M. Ward, and Jerry Kaplan. "Expression of the Yeast Cation Diffusion Facilitators Mmt1 and Mmt2 Affects Mitochondrial and Cellular Iron Homeostasis." Journal of Biological Chemistry 289, no. 24 (May 5, 2014): 17132–41. http://dx.doi.org/10.1074/jbc.m114.574723.
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Kim, Young Ho, Jeong-Woo Sohn, Youngjae Woo, Joo-Hyun Hong, Gyu Man Kim, Bong Keun Kang, and Juyoung Park. "Preparation of Microstructure Molds of Montmorillonite/Polyethylene Glycol Diacrylate and Multi-Walled Carbon Nanotube/Polyethylene Glycol Diacrylate Nanocomposites for Miniaturized Device Applications." Journal of Nanoscience and Nanotechnology 15, no. 10 (October 1, 2015): 7860–65. http://dx.doi.org/10.1166/jnn.2015.11224.
Повний текст джерелаАнотація:
Environmentally friendly microstructure molds with montmorillonite (MMT) or multi-walled carbon nanotube (MWCNT) reinforced polyethylene glycol diacrylate (PEGDA) nanocomposites have been prepared for miniaturized device applications. The micropatterning of MMT/PEGDA and MWCNT/PEGDA with 0.5 to 2.0 wt% of MMTs and MWCNTs was achieved through a UV curing process with micro-patterned masks. Hexagonal dot arrays and complex patterns for microstructures of the nanocomposites were produced and characterized with an optical microscope; their thermal properties were studied by thermogravimetric analysis (TGA). The TGA results showed that these nanocomposites were thermally stable up to 350 °C. Polydimethylsiloxane thin replicas with different microstructures were prepared by a casting method using the microstructured nanocomposites as molds. It is considered that these microstructure molds of the nanocomposites can be used as microchip molds to fabricate nanobio-chips and medical diagnostic chip devices.
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Honegger, Andrew, Shiv G. Kapoor, and Richard E. DeVor. "A Hybrid Methodology for Kinematic Calibration of Micro/Meso-Scale Machine Tools (mMTs)." Journal of Manufacturing Science and Engineering 128, no. 2 (November 1, 2005): 513–22. http://dx.doi.org/10.1115/1.2162910.
Повний текст джерелаАнотація:
A trigger probe measurement system and measurement methodology are developed for kinematic self-calibration of micro/meso-scale machine tools (mMTs). The trigger probe detects the contact between a spindle-mounted stylus and a table-mounted planar artifact. The trigger probe system is small enough to be easily mounted on an mMT. The measurement methodology is divided into off-machine and on-machine measurements. The off-machine measurements are only needed for the first calibration. Recalibration requires only the on-machine measurements to be repeated, thereby reducing recalibration time. The measurement system and methodology are implemented with existing kinematic modeling, error parameter estimation, and compensation techniques for the experimental calibration of a three-axis mMT. The measurement system error is evaluated and experimentally measured. Cutting tests are used to validate the performance of the calibration methodology.
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Huber, Veronika, Cristina Peña Ortiz, David Gallego Puyol, Stefan Lange, and Francesco Sera. "Evidence of rapid adaptation integrated into projections of temperature-related excess mortality." Environmental Research Letters 17, no. 4 (April 1, 2022): 044075. http://dx.doi.org/10.1088/1748-9326/ac5dee.
Повний текст джерелаАнотація:
Abstract Few studies have used empirical evidence of past adaptation to project temperature-related excess mortality under climate change. Here, we assess adaptation in future projections of temperature-related excess mortality by employing evidence of shifting minimum mortality temperatures (MMTs) concurrent with climate warming of recent decades. The study is based on daily non-external mortality and daily mean temperature time-series from 11 Spanish cities covering four decades (1978–2017). It employs distributed lag non-linear models (DLNMs) to describe temperature-mortality associations, and multivariate mixed-effect meta-regression models to derive city- and subperiod-specific MMTs, and subsequently MMT associations with climatic indicators. We use temperature projections for one low- and one high-emission scenario (ssp126, ssp370) derived from five global climate models. Our results show that MMTs have closely tracked mean summer temperatures (MSTs) over time and space, with meta-regression models suggesting that the MMTs increased by 0.73 °C (95%CI: 0.65, 0.80) per 1 °C rise in MST over time, and by 0.84 °C (95%CI: 0.76, 0.92) per 1 °C rise in MST across cities. Future projections, which include adaptation by shifting MMTs according to observed temporal changes, result in 63.5% (95%CI: 50.0, 81.2) lower heat-related excess mortality, 63.7% (95%CI: 30.2, 166.7) higher cold-related excess mortality, and 11.2% (95%CI: −5.5, 39.5) lower total temperature-related excess mortality in the 2090s for ssp370 compared to estimates that do not account for adaptation. For ssp126, assumptions on adaptation have a comparatively small impact on excess mortality estimates. Elucidating the adaptive capacities of societies can motivate strengthened efforts to implement specific adaptation measures directed at reducing heat stress under climate change.
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Dunga, S. K., C. Kavadichanda, and V. Negi. "POS0880 TWO-MINUTE WALK TEST AS A SIMPLE AND OBJECTIVE OUTCOME MEASURE IN IDIOPATHIC INFLAMMATORY MYOSITIS." Annals of the Rheumatic Diseases 80, Suppl 1 (May 19, 2021): 696.2–696. http://dx.doi.org/10.1136/annrheumdis-2021-eular.3461.
Повний текст джерелаАнотація:
Background:Manual muscle testing (MMT) and Functional index 2(FI-2) are the usual methods in assessing disease activity in IIM1. Limitations of MMT8 include low sensitivity to change, floor/ceiling effect, and under-representation of certain important muscle groups1 while FI-2 takes a longer time to administer. Several Timed function tests (TFTs) like the 2-minute walk test (2MWT) or 30s raise from a chair test and 30s 1kg arm rise test may be better alternatives and less time taking2. Data looking at the performance of these tests are limited to small controlled studies.Objectives:To assess the performance of timed function tests against MMT8 and FI-2 in assessing muscle strength and endurance at baseline, 3 and 6 months of therapy.Methods:An observational cohort study, included 41 patients with polymyositis and dermato-myositis attending OPD and IPD service of tertiary centre. MMT8, FI-2 and Timed function tests were done at baseline, at 3 months and at 6 months. (Figure 1)Figure 1.Consort diagram showing the workflow in study populationResults:Forty one patients included in the study had completed three month follow-up assessment, while 17 patients achieved a six-month evaluation. Out of 41 patients, 11 (27%) were polymyositis, and 30 (73%) were dermatomyositis. The mean MMT8 of the total study population at baseline was 57±15, at three months (n=41) was 66 ±10 and at six months (n=17) was 71 ± 10, while in active subgroup was 50 ± 18, 64 ± 9 (n=41), 67 ± 9.6 (n=17)at baseline, three months and six months respectively. The change in TFTs showed a moderate to strong correlation with the change in Fi-2 among the study population at three months and six months (Table 2). Among the TFTs 2MWT showed moderate correlation with both MMT8 and FI-2 in active disease.Table 1.Spearman Rho Correlation between change in timed function tests with change in MMT8, change in FI-2 at 3 months and 6 monthsAt 3 months (n=41)At 6 months (n=17)Active disease(n=18)Inactive disease(n=23)Active disease(n=7)Inactivedisease(n=10)Correlation of Δ MMT8 withΔ30s rise form chair0.1430.3460.2000.347Δ30s1kg arm lift0.0180.2840.3620.168Δ2MWD0.755*0.3130.482*0.334Correlation of ΔFI-2 withΔ30s rise form chair0.784*0.495*0.486*0.424*Δ30s1kg arm lift0.671*0.1070.704*0.301Δ2MWD0.834*0.623*0.808*0.506**p<0.05Conclusion:Using timed function tests can be an excellent alternative to FI-2 in assessing muscle endurance. 2-minute walk distance is a better alternative to conventional muscle testing as it measures both power and endurance, and this can overcome the ceiling effect of MMT-8.References:[1]Rider LG, Aggarwal R, Machado PM, Hogrel J-Y, Reed AM, Christopher-Stine L, et al. Update on outcome assessment in myositis. Nat. Rev. Rheumatol. 2018;14:303–18.[2]Agarwal S, Kiely PD. Two simple, reliable and valid tests of proximal muscle function, and their application to the management of idiopathic inflammatory myositis. Rheumatology. 2006 Jul 1;45(7):874-9.Acknowledgements:I would like to acknowledge my patients, my teachers, colleagues, and paraclinical staff of the department of Clinical Immunology JIPMERDisclosure of Interests:None declared
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Mutavdžin, Dejana, Milan Stančić, and Blanka Bogunović. "To be connected: Supporting self-regulated learning in higher music education before and during the pandemic." Psiholoska istrazivanja 24, no. 2 (2021): 277–301. http://dx.doi.org/10.5937/psistra24-32702.
Повний текст джерелаАнотація:
In online learning, students are expected to take on more responsibility for their education, while teachers are expected to support students' self-regulated learning (SRL) skills. In this research, we explore whether young musicians perceive a difference in the actions that their major music teacher (MMT) took to support their SRL skills before and during the pandemic, and investigate their view on how the MMT could further support their learning. The sample included 144 students of the Faculty of Music in Belgrade, who filled in the online inventory comprised of 24 questions - 17 parallel Likert-type items (referring to the MMT's actions supporting SRL skills, before and during the pandemic), and one question was a short letter to the MMT. Data were analysed using dependent t-test, ANOVA and reflexive thematic analysis. Students perceived that SRL skills were more encouraged before than during the pandemic. Additionally, our findings show that music students who did not have in-person and online communication, separately, with their MMTs perceived they had lower support to self-regulate their learning. The findings from qualitative analysis inform educational practice by pointing to specific teacher's actions that students perceive as important for their further development.
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AUYEZKHANOVA, Assemgul S., Eldar T. TALGATOV, Sandugash N. AKHMETOVA, Unzira N. KAPYSHEVA, and Alima K. ZHARMAGAMBETOVA. "SYNTHESIS AND PROTECTIVE PROPERTIES OF PECTIN/MONTMORILLONITE COMPOSITES AGAINST ASPIRIN-INDUCED ENTEROCOLITIS." Periódico Tchê Química 17, no. 35 (July 20, 2020): 897–907. http://dx.doi.org/10.52571/ptq.v17.n35.2020.74_auyezkhanova_pgs_897_907.pdf.
Повний текст джерелаАнотація:
Long term use of aspirin for prevention of cardiovascular events is limited by its gastrointestinal adverse effects, and, therefore, patients at high risk should receive gastroprotective agents. However, gastroprotective drugs also have a few adverse effects that require searching for safe and effective alternatives. The composites combining the swelling properties of clays and the biological activity of polysaccharides seem to be promising candidates for gastrointestinal protection. This study aimed to characterize pectin/montmorillonite composites and evaluate their protective effect on the gastrointestinal tract of rats taking aspirin over a long period. A series of composites based on montmorillonite (ММТ) and low esterified pectin (Pec) was synthesized using the adsorption-precipitation method. The polysaccharide to clay weight ratios were 1:19, 1:9, and 1:4. The composites were characterized using Thermogravimetric Analysis (TGA), Infrared Spectroscopy (IR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). Pectin was completely fixed on MMT, and the polysaccharide content in the composites was approximately 5, 10, and 20 wt%, respectively. The shifting of the absorption band of the C=O group of the pectin indicated the interaction of the polysaccharide with the clay, confirming effective immobilization of Pec on MMT. Modification with pectin changed the morphology and structure of the MMT due to the surface coating and intercalation into the interlayer space. The composites swelled in acidified water (pH = 2.0), and their swelling ability was higher to compare with unmodified MMT. The sorption capacity of Pec/MMT composites towards acetylsalicylic acid (ASA) was decreased from 6.8 to 1.0 mg g-1 with increasing of pectin content from 5 to 20 wt%. The hybrid composites promoted the protection of the gastrointestinal tract of rats, which were administered ASA with Pec/MMTs for 16 days. Protective properties of the Pec/MMT have been improved with increasing pectin content from 5 to 20 wt%.
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Corobov, Roman, Scott Sheridan, Kristie Ebi, and Nicolae Opopol. "Warm Season Temperature-Mortality Relationships in Chisinau (Moldova)." International Journal of Atmospheric Sciences 2013 (February 19, 2013): 1–9. http://dx.doi.org/10.1155/2013/346024.
Повний текст джерелаАнотація:
Results of the epidemiological study of relationships between air temperature and daily mortality in Chisinau (Moldova) are presented. The research’s main task included description of mortality dependence on different temperature variables and identification of thermal optimum (minimal mortality temperature, MMT). Total daily deaths were used to characterize the mortality of urban and rural populations in April–September of 2000–2008, excluding the extremely warm season of 2007. The simple moving average procedure and 2nd-order polynomials were used for daily mean (Tmean), maximum (Tmax), and minimum (Tmin) temperatures and mortality approximation. Thermal optimum for mortality in Chisinau (15.2 deaths) was observed at Tmean, Tmax, and Tmin about 22°C, 27-28°C, and 17-18°C, respectively. Considering these values as certain cut-points, the correlations between temperature and mortality were estimated below and above MMTs. With air temperatures below its optimal value, each additional 1°C increase of Tmean (Tmax, Tmin) was accompanied by 1.40% (1.35%, 1.52%) decrease in daily mortality. The increase of Tmean and Tmax above optimal values was associated with ~2.8% and 3.5% increase of mortality; results for Tmin were not statistically significant. The dependency of mortality on apparent temperature was somewhat weaker below MMT; a significant relationship above MMT was not identified.
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Bittmann, Frank, Silas Dech, Markus Aehle, and Laura Schaefer. "Manual Muscle Testing—Force Profiles and Their Reproducibility." Diagnostics 10, no. 12 (November 25, 2020): 996. http://dx.doi.org/10.3390/diagnostics10120996.
Повний текст джерелаАнотація:
The manual muscle test (MMT) is a flexible diagnostic tool, which is used in many disciplines, applied in several ways. The main problem is the subjectivity of the test. The MMT in the version of a “break test” depends on the tester’s force rise and the patient’s ability to resist the applied force. As a first step, the investigation of the reproducibility of the testers’ force profile is required for valid application. The study examined the force profiles of n = 29 testers (n = 9 experiences (Exp), n = 8 little experienced (LitExp), n = 12 beginners (Beg)). The testers performed 10 MMTs according to the test of hip flexors, but against a fixed leg to exclude the patient’s reaction. A handheld device recorded the temporal course of the applied force. The results show significant differences between Exp and Beg concerning the starting force (padj = 0.029), the ratio of starting to maximum force (padj = 0.005) and the normalized mean Euclidean distances between the 10 trials (padj = 0.015). The slope is significantly higher in Exp vs. LitExp (p = 0.006) and Beg (p = 0.005). The results also indicate that experienced testers show inter-tester differences and partly even a low intra-tester reproducibility. This highlights the necessity of an objective MMT-assessment. Furthermore, an agreement on a standardized force profile is required. A suggestion for this is given.
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Magalhaes, Luiz, and Robin Kravets. "MMTP." ACM SIGCOMM Computer Communication Review 31, no. 2 supplement (April 2001): 220–43. http://dx.doi.org/10.1145/844193.844207.
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Dunga, S. K., A. M B, C. Kavadichanda, and V. Negi. "SAT0314 TIMED FUNCTION TESTS ARE AN ALTERNATIVE TO MMT8 AND FI-2 IN INFLAMMATORY MYOSITIS - AN OBSERVATIONAL COHORT STUDY." Annals of the Rheumatic Diseases 79, Suppl 1 (June 2020): 1102–3. http://dx.doi.org/10.1136/annrheumdis-2020-eular.6078.
Повний текст джерелаАнотація:
Background:Inflammatory myositis are heterogenous group of diseases affecting skeletal muscles and multiple different organs1. Manual muscle testing (MMT) is the common tool used for assessment of muscle strength. Its limitations include poor sensitivity to change, floor/ceiling effect, and under representation of certain important muscle groups2. Functional index 2(FI-2) is an objective measure of dynamic repetitive muscle function at 11 proximal and distal muscle groups which correlates well with patient-reported physical function3. Since MMT8 is inadequate and FI-2 takes longer time to administer, several timed tests to assess muscle function, endurance and fatiguability like the 2- minute walk test (2MWT) or 30s raise from a chair test and 30s arm rise test are viable alternatives to be tested. Data looking at the performance of these tests are limited to small controlled studies.Objectives:To study correlation of timed tests with MMT8 and FI-2 in assessing muscle strength, endurance at baseline and at 3 months of therapy.Methods:An observational cohort study, included 19 patients with polymyositis and dermatomyositis attending OPD and IPD service of tertiary center. Patients with nclusion body myositis, overlap myositis, chronic kidney disease, coexisting myocarditis, sepsis, malignancy, pregnancy were excluded. MMT8, FI-2 and Timed function tests were done at baseline and after 3 months.Results:The study had 19 patients of which 6 were polymyositis and 13 were dermatomyositis. Male to female ratio was 1:2.1. Anti-cell antibody was positive in 16 patients. The mean MMT8 of the study group at baseline was 60.84±16.77 and after 3 months was 67.05±11.7. Out of 19 patients, all received prednisolone as induction agent followed by Methotrexate in 13, cyclophosphamide in 9, azathioprine in 5, Rituximab by one patient. Mean scores of 30s arm lift, 30s rise from chair test and 2 min walk test were 11.7±6.39,14±7.29,101.5± 46.48 respectively at baseline and 13.05±6.5,15.6±7.1,117.84±38.4 after 3 months.Table 1.Spearman Rho Correlation between timed function tests and MMT8, FI-2, patient and physician VASΔ 30s rise from chair testΔ 30s arm lift testΔ 2 min walk testΔ MMT80.3820.3370.724**Δ FI-2Hip flexion right0.3880.4130.314Hip flexion Left0.503*0.4160.422Neck flexion0.600**0.590**0.610**Shoulder flexion right0.1830.3000.239Shoulder flexion left0.3930.2220.207Shoulder abduction right0.2360.2220.348Shoulder abduction left0.1820.2360.273Step test right0.744**0.489*0.326Step test left0.8400.500*0.378Heel rise0.4420.2940.388Toe rise0.4460.2910.419Δ Physician VAS-0.508*-0.506**-0.215Δ Patient VAS-0.600**-0.597**-0.249Δ → change from baseline to 3 months *→ Correlation is significant at the 0.05 level **→ Correlation is significant at the 0.01 levelConclusion:Timed function tests correlated well with MMT 8 and parameters with in FI-2. Thus these tests are good alternatives in assessing disease activity and response assessment in inflammatory myositis.References:[1]Selva-O’Callaghan A, Pinal-Fernandez I, Trallero-Araguás E, Milisenda JC, Grau-Junyent JM, Mammen AL. Classification and management of adult inflammatory myopathies. Lancet Neurol. 2018; 17:816–28.[2]Rider LG, Aggarwal R, Machado PM, Hogrel J-Y, Reed AM, Christopher-Stine L, et al. Update on outcome assessment in myositis. Nat. Rev. Rheumatol. 2018;14:303–18.[3]Alexanderson H, Broman L, TollbÄck A, Josefson A, Lundberg IE, StenstrÖm CH. Functional index-2: Validity and reliability of a disease-specific measure of impairment in patients with polymyositis and dermatomyositis. Arthritis Rheum. 2006;55:114–22.Disclosure of Interests: :None declared
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Koirala, Naba Raj, Sharma Vidya Dev, Saroj Prasad Ojha, and Nishita Pathak. "Prevalence of anxiety symptoms among the clients maintained in methadone maintenance treatment programme at Tribhuvan University Teaching Hospital." Journal of Nobel Medical College 1, no. 1 (December 28, 2012): 15–19. http://dx.doi.org/10.3126/jonmc.v1i1.7283.
Повний текст джерелаАнотація:
Background: The symptoms of anxiety are widely prevalent among the former opioid addicts in methadone maintenance treatment (MMT). It is clinically important to be aware of the severity of the co-morbidity as it plays a crucial role in the methadone dosage, length of time in treatment and the relapse rate and the co-existence of co-morbidity has been described as the factor which worsens the prognosis. Aim: to study the prevalence of the symptoms of anxiety among MMT clients Methods: a descriptive, survey and a cross- sectional study, 60 MMT clients were selected who had been attending the MMTP for more than 2 months and were given with semistructured proforma specifically designed for this study only. Then after, they were evaluated for the anxiety symptoms with Beck Anxiety Inventory (BAI). Finally, the information obtained from the demographic profile and the rating scale were analyzed with the help of computer program SPSS. Results: The study showed around 41.7 % of the patients had symptoms of anxiety with varying severity. Correlates of presence of anxiety symptom among MMT client in the present study showed higher prevalence among age group 20-29(88%), 66% were separated and 64% were unmarried, 50% were Buddhist, majority of the case were chhetri (70%), 75% had primary level education, 67% were unemployed, and 65% from middle class socioeconomic status. Limitation: The study was a cross sectional, which showed only the symptoms of anxiety not the disorder and the drug use, withdrawals itself, could distort evaluation and lead to misdiagnosis of anxiety. Conclusion: The major risk factor for was male gender, separated, primary education level, students and middle socio-economic status.DOI: http://dx.doi.org/10.3126/jonmc.v1i1.7283 Journal of Nobel Medical College Vol.1(1) 2011 15-19
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Brennan, Patrick T., Jesus M. Villa, Mark D. Rossi, Marcos A. Sanchez-Gonzalez, and Carlos J. Lavernia. "Rehabilitation Outcomes for Total Knee Arthroplasties: Continuous Adductor Canal Block Versus Continuous Femoral Nerve Block." Geriatric Orthopaedic Surgery & Rehabilitation 9 (January 1, 2018): 215145851875619. http://dx.doi.org/10.1177/2151458518756190.
Повний текст джерелаАнотація:
Objective: To determine whether any strength, range of motion (ROM), or functional improvement exists in the adductor canal block (ACB) group after completion of inpatient rehabilitation and following the removal of the continuous block. Design: Retrospective cohort. Setting: Inpatient rehabilitation at discharge and outpatient orthopedic clinic for follow-up. Participants: Two hundred forty-six consecutive primary total knee arthroplasties (TKAs; N = 221 patients) performed by a single surgeon in a single institution between July 2013 and August 2015 for a diagnosis of osteoarthritis. Interventions: All TKA cases received a continuous femoral nerve block (FNB) from July 2013 to August 2014 for postoperative pain control. From August 2014 through August 2015, all TKAs received a continuous ACB. Main Outcome Measures: Manual muscle tests (MMTs; 0-5 scale) of the quadriceps and passive ROM of the knee were assessed at 3 time periods (hospital discharge [HD], 1-2 weeks, and 1 month). Patient-oriented outcomes and clinical knee scores were examined preoperatively and postoperatively at 3 and 6 months. Results: 63.6% of FNB cases had an MMT less than 3 at HD and 36.4% of FNB cases had an MMT of 3 or greater at HD. Conversely, 46% of ACB cases had an MMT less than 3 at HD and 54% had an MMT of 3 or greater at HD. There were no statistically significant differences in all postoperative variables at all tested time periods. Conclusions: This study showed no short-term postoperative advantages in the ACB group after catheter removal. The superior inpatient rehabilitation course in the continuous ACB group is likely not long enough to translate into any maintained benefit following catheter removal. Nevertheless, the trend toward greater strength in the ACB group in the immediate short term at HD warrants further investigation.
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Abbasian, Mojtaba, and Farideh Mahmoodzadeh. "Synthesis of antibacterial silver–chitosan-modified bionanocomposites by RAFT polymerization and chemical reduction methods." Journal of Elastomers & Plastics 49, no. 2 (July 27, 2016): 173–93. http://dx.doi.org/10.1177/0095244316644858.
Повний текст джерелаАнотація:
Chitosan (Cts) was first modified with 4-cyano,4-[(phenylcarbothioyl)sulfanyl]pentanoic acid to serve as reversible addition–fragmentation chain transfer (RAFT) agent, and then the controlled grafting polymerizations of acrylic acid (PAA) were performed. The resultant copolymers were used as a stabilizing agent for preparation of colloidal silver nanoparticles (Ag NPs) in the range of 2–10 nm. Afterwards, montmorillonites (MMTs) were added to the solution of colloidal Ag NPs for improving thermal stability. Proton nuclear magnetic resonance spectroscopy, Fourier transform infrared spectrometry, energy dispersive X-ray spectroscopy, X-ray diffraction analysis, and scanning electron microscopy images demonstrate the successful synthesis of the graft copolymer. Their thermal behavior was examined by differential scanning calorimetry and thermogravimetric analyses.The antibacterial activity of Ag/Cts-g-PAA and Ag/Cts-g-PAA/MMT was investigated against Staphylococcus aureus, Escherichia coli, and Candida albicans by the disc diffusion method using Mueller Hinton agar. Antimicrobial tests show that Ag/Cts-g-PAA has much higher antimicrobial activity than Ag/Cts-g-PAA/MMT. This method would enable a wide variety of molecular designs to afford novel types of tailored hybrid materials composed of natural polysaccharides and synthetic polymers. The new hybrid materials were used as a stabilizing agent for preparation of Ag bionanocomposites with good antibacterial activity.
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Zhang, Debin, Xiaofang Cheng, and Peiqi Wang. "Study on Calculation of Minimum Thickness of Sample in Thermal Conductivity Measurement." Advances in Engineering Technology Research 1, no. 1 (May 17, 2022): 271. http://dx.doi.org/10.56028/aetr.1.1.271.
Повний текст джерелаАнотація:
It is found that the true thermal conductivity can be measured only when material reaches a certain minimum thickness, within which the thermal conductivity varies with thickness. Based on the derivative of Fourier's law, it is pointed out that the phenomenon of thermal conductivity varying with thickness is caused by the existence of second derivative of temperature. Both of the FTC (function of thermal conductivity) and the calculation formula of MMT (minimum measured thickness) are established. For materials of GFRP (glass fiber reinforced plastic), neoprene and silicone, their R-squared of FTC are respectively 0.9995, 0.9668 and 0.9976, and their MMTs are 5.2287 mm, 4.7034 mm and 12.7532 mm, respectively. What’s more, their interfacial thermal conductivities are different, which reveals that thermal conductivity of material is a numerical field.
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Pospiech, Doris, Andreas Korwitz, Hartmut Komber, Dieter Voigt, Dieter Jehnichen, Jan Müller, Andreas Janke, Thorsten Hoffmann, and Bernd Kretzschmar. "In situ Synthesis of Poly(ethylene terephthalate)/layered Silicate Nanocomposites by Polycondensation." High Performance Polymers 19, no. 5-6 (October 2007): 565–80. http://dx.doi.org/10.1177/0954008307081199.
Повний текст джерелаАнотація:
The goal of the work presented here was to develop nanocomposites consisting of layered silicates and poly(ethylene terephthalate) (PET). Two nanocomposite preparation methods were compared: first, the usual melt compounding technique, and second, in-situ synthesis of PET in presence of different types of layered silicates. Montmorillonite (MMT) without and with organophilic modification was employed as layered silicate. In most cases, PETs with acceptable properties (molecular weight and discoloration) were synthesized in presence of different MMTs although the molecular weights of the in-situ PETs were lower than the control sample. These materials were used as masterbatch for PET nanocom-posites with 5 wt.% inorganic content. The exfoliation in both types of nanocomposites was not complete, but they showed a good distribution of clay within the polymer matrix.
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Park, Sang-Cheol, Ho-Gyum Kim, and Kyung-Eun Min. "Effect of MMT on Anti-Water Absorption of Polyamide/MMT Nanocomposites." Polymer Korea 37, no. 1 (January 25, 2013): 113–20. http://dx.doi.org/10.7317/pk.2013.37.1.113.
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LeBlanc, Gabby, Brandon Brooks, Madeline Hartman, Maxwell B. Hecht, Hoa Luong, Zheng Pan, Stephen Sofen, et al. "737. Novel Glycans Reduce Carbapenem-Resistant Enterobacteriaceae and Vancomycin-Resistant Enterococci Colonization in an Ex Vivo Assay by Supporting Growth and Diversity of Commensal Microbiota at the Expense of MultiDrug-Resistant Organisms (MDRO)." Open Forum Infectious Diseases 6, Supplement_2 (October 2019): S330. http://dx.doi.org/10.1093/ofid/ofz360.805.
Повний текст джерелаАнотація:
Abstract Background Infections with Carbapenem-resistant Enterobacteriaceae (CRE) and vancomycin-resistant Enterococci (VRE) can result in a 50% mortality rate in compromised hosts. A major risk factor for clinical infection is intestinal colonization with CRE or VRE. There are currently no FDA-approved compounds to decolonize these organisms from the gastrointestinal tract (gut). Commensal microbes offer protection from pathogen infection; however, in immunocompromised hosts or with antibiotic treatment, the protective properties of the microbial community are compromised, leaving the gut susceptible to pathogen colonization. Higher concentrations of pathogens within the gut correlate with an increased risk of infection with MDROs. Our hypothesis is that reducing colonization of the gut with MDROs would reduce the likelihood of a clinical infection. Methods Kaleido built a platform that emulates the gut environment and allows for high throughput screening of Kaleido’s Microbiome Metabolic Therapies (MMT™) in human gut microbiomes ex vivo. Over 500 compounds were screened for their ability to reduce the levels of CRE and VRE in fecal microbial communities from both healthy subjects and critically ill patients receiving broad-spectrum antibiotics. Results Kaleido’s lead MMTs selectively favor the growth of the commensal microbiota at the expense of pathogens, resulting in a decrease of CRE and VRE from 80% of the initial community to 5% in a single batch culture, as measured by 16S rRNA gene and shotgun metagenomic sequencing. Lead MMTs do not support growth of CRE and VRE strains in culture, nor of other pathogens frequently encountered in critically ill and immunocompromised patients, such as Clostridium difficile and common fungal pathogens. Conclusion These results suggest that intervention with MMTs may reduce CRE and VRE colonization and support further evaluation in patients colonized with CRE or VRE pathogens. Disclosures All authors: No reported disclosures.
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Gorijavolu, M., D. Bairwa, C. Kavadichanda, A. Gopal, S. K. Dunga, M. M. Thabah, and V. Negi. "POS0392 ROLE OF SEMIQUANTITATIVE THIGH MAGNETIC RESONANCE IMAGING (tMRI) IN DETERMINING SKELETAL MUSCLE OUTCOMES AT BASELINE AND ON FOLLOW UP IN IDIOPATHIC INFLAMMATORY MYOPATHIES (IIMs)." Annals of the Rheumatic Diseases 81, Suppl 1 (May 23, 2022): 451.2–452. http://dx.doi.org/10.1136/annrheumdis-2022-eular.4993.
Повний текст джерелаАнотація:
BackgroundIdiopathic Inflammatory Myopathies (IIMs) are characterized by muscle inflammation and associated muscle weakness. Semiquantitative scoring of thigh Magnetic Resonance Imaging (tMRI) has shown contradictory results in associating muscle inflammation, damage, and clinically assessed muscle weakness. Moreover, there are no studies assessing the role of tMRI detected muscle damage in determining long-term recovery of muscle strength and endurance.ObjectivesTo correlate tMRI scores for muscle edema, fascial edema, muscle atrophy, and fatty infiltration with consecutively collected manual muscle testing 8 (MMT-8) scores and muscle enzymes. To determine the role of baseline tMRI changes in achieving maximum muscle power during follow-up.MethodsThis is a retrospective analysis of a single-center myositis cohort. IIM patients (n=55) who underwent baseline tMRI (STIR and T1 sequences) at the time of diagnosis were included. Baseline demographic, clinical, and serological parameters were noted. MRI T1 weighted sequence and STIR sequence axial and coronal images were assessed for intramuscular and fascial edema, atrophy and fatty replacement using a semiquantitative score and the percentage of muscle involvement for each parameter was calculated. MMT-8 values and muscle enzyme levels which remained unchanged at least for 6 months during follow-up were noted for 42 patients. MMT-8 ≥74 was taken as near normal muscle power based on the fact that 75% of IIM patients in remission for a long duration achieved MMT-8 of≥74 in our cohort. Spearman correlation was done between clinical parameters, muscle enzymes, and tMRI scores. Baseline parameters of patients who achieved and did not achieve MMT8≥74 were compared. Multiple linear regression was performed to assess the tMRI variables predicting a higher MMT-8 during follow-upResultsThe median age was 36 (27.25-44.75) years, median duration of disease at presentation was 4 months (2-10), median duration of follow up was 24 months (6.75-38.25). Dermatomyositis, Polymyositis and Antisynthetase syndrome comprised of 58.2%, 7.3% and 30.9% cases respectively. Baseline muscle enzymes CPK(r=0.531), AST(r=0.535) and ALT(r=0.442) showed significant positive correlation(p<0.01) with muscle edema. Baseline MMT-8 showed significant negative correlation with muscle edema(r=-0.657) and fascial edema(r=-0.522) (p<0.01). Follow up MMT-8 showed significant negative correlation with muscle edema(r=-0.359), muscle atrophy (r=-0.319) and fatty infiltration(r=-0.308) (p<0.05) (Figure 1). Baseline MMT-8 and MRI fatty infiltration were significantly different between patients who achieved and did not achieve MMT-8 of ≥74 on follow-up (Table 1). Multiple regression analysis revealed adjusted R2 value of 0.386. Baseline MMT-8(β=0.372) and muscle atrophy(β=-0.459) significantly predicted MMT-8 on follow-upTable 1.Comparison between those who achieved near-normal muscle power versus othersFollow up MMT-8<74 (n=8)Follow up MMT-8 ≥74 (n=34)P-valueAge (years) (median, IQR)36.5(27-47.5)36(28.75-44.25)1.000Duration of disease (months) (median, IQR)6(4-10.5)3.5(2.75-9.75)0.459Baseline muscle enzymes and MMT-8 (median, IQR)CPK (IU/L)1758(116-6160)680(57.5-3595)0.410LDH (IU/L)496(240-823)616.50(289.25-753)0.672AST (IU/L)112(76-201.5)69.5(40.5-226.25)0.352ALT (IU/L)74.50(65.5-139.75)69(36-142.25)0.560MMT-8 baseline (0-80)49.5(47.25-56)63(53.75-73.25)0.007MRI thigh scores (median, IQR)Muscle edema%22.41(5.65-63.33)10.37(0.00-28.70)0.070Fascial edema %43.33(18.61-78.06)33.89(11.49-50.56)0.478Muscle atrophy %2.22(0.28-20.83)0.00(0.00-2.50)0.081Fatty infiltration %6.67(2.78-18.61)0.56(0.00-3.61)0.010Figure 1.Correlation between baseline and Follow up MMT-8 with tMRI scores.ConclusionLow baseline MMT-8 and presence of muscle atrophy at baseline are predictors of poor outcome. Hence performing a baseline MRI will help in the prognosis.Disclosure of InterestsNone declared
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Wiel, Eric, Christophe Di Pompéo, Nicolas Segal, Gérald Luc, Jean-Baptiste Marc, Carine Vanderstraeten, Carlos El Khoury, et al. "Age discrimination in out-of-hospital cardiac arrest care: a case-control study." European Journal of Cardiovascular Nursing 17, no. 6 (December 5, 2017): 505–12. http://dx.doi.org/10.1177/1474515117746329.
Повний текст джерелаАнотація:
Background: Although some studies have questioned whether cardiopulmonary resuscitation (CPR) in older people could be futile, age is not considered an essential out-of-hospital cardiac arrest (OHCA) prognostic factor. However, in the daily clinical practice of mobile medical teams (MMTs), age seems to be an important factor affecting OHCA care. Aims: The purpose of this study was to compare OHCA care and outcomes between young patients (<65 years old) and older patients. Methods: We performed a case-control study based on data extracted from the French National Cardiac Arrest (CA) registry. All adult patients with CA recorded between July 2011 and May 2014 were included. Each older patient was matched on three criteria: sex, initial cardiac rhythm and no-flow duration. Results: We studied 4347 pairs. We found significantly less basic life support initiation, shorter advanced cardiac life support duration, less MMT automated chest compression, less MMT ventilation and less MMT epinephrine injection in the older patients. Significant differences were also observed for return of spontaneous circulation (odds ratio (OR)=0.84, 95% confidence interval (CI) 0.77–0.92, p<0.001), transport to hospital (OR=0.58, 95% CI 0.51–0.61, p<0.001), vital status at hospital admission (OR=0.55, 95% CI 0.50–0.60, p<0.001) and vital status 30 days after CA (OR=0.42, 95% CI 0.35–0.50, p<0.001). Conclusion: All OHCA guidelines, ethical statements and clinical procedures do not propose age as a discrimination criterion in OHCA care. However, in our case-control study, we notice a shorter duration and less intensive care among older patients. This finding may partly explain the lower survival rate compared with younger people.
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Shrestha, DM, TK Aich, K. Gautam, and D. Bajracharya. "Opioid Dependence And Methadone Maintenance Treatment (MMT) Programme In Nepal In Three Different Decades: An Exploratory/Comparative Study." Journal of Psychiatrists' Association of Nepal 9, no. 2 (December 31, 2020): 3–11. http://dx.doi.org/10.3126/jpan.v9i2.36278.
Повний текст джерелаАнотація:
Introduction: First Methadone Maintenance Programme (MMTP) in Nepal was started in the year 1994. This study was done to study and explore/compare findings of the present study with that of studies published in Nepal in the new millennium.
Material and Method: Study was conducted at the Mental Hospital, Lalitpur, Kathmandu, Nepal from 1994 to 2002. Data was collected for the initial 5 years from 1994 to 1998. These patients were followed up for the next five years till 2002. Data thus obtained are presented in a tabulated form, in terms of frequencies and percentages.
Results: A total of 204 patients were put on Methadone Maintenance Treatment Programme (MMTP) during the scheduled period. One-hundred-and-twenty-two (60%) of them were abusing buprenorphine. Severity of buprenorphine abuse was between 1-6 ampoules (2 ml per ampoule) per day. Approximately 40% (81) of them were sharing the injecting equipment. Seventy-seven (38%) of them had been in police custody in the past, for various reasons like theft, cheating, possessing, trafficking, violence and other antisocial behaviours. Forty-five percent (92) clients were retained at the end of 5 years. Sixty-nine family members (spouses, mothers, brothers) from these 92 regular methadone clients were interviewed. Eighty-six percent (79) of the interviewed family members reported significant improvement in clients’ health. Eighty-one percent (75) of the family members reported significant improvement among the methadone users’ family in financial responsibilities and interest in work. Overall, MMTP was found to have reduced the amount of illicit drug abuse significantly in these patients. These results are compared with the data of the subsequent published data on MMTP from Nepal in the new millennium.
Conclusion: Though the present study data may appear to be of historical value, we are presenting these data, in the light of the findings of the newer studies published of late from Nepal. Till date, our study remained the largest MMT Programme in Nepal, in terms of number of patients studied, number of years of study and number of years of follow up of these patients.
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Heyworth, Benton, Madison Brenner, Elizabeth Adsit, Matthew Millewski, Eric Edmonds, Philip Wilson, Kevin Shea, and Henry Ellis. "Poster 224: Tear Features and Surgical Techniques in 1230 Child and Adolescent Meniscus Repairs: Results from a Prospective, Multicenter Registry." Orthopaedic Journal of Sports Medicine 10, no. 7_suppl5 (July 1, 2022): 2325967121S0078. http://dx.doi.org/10.1177/2325967121s00785.
Повний текст джерелаАнотація:
Objectives: Recent literature has suggested a marked shift towards increased meniscus repair relative to meniscectomy over the last decade in younger populations. Children and adolescents are more profoundly impacted by the outcomes of meniscus preservation, in terms of long-term joint health, given the subsequent decades of high activity levels, risk of meniscus re-injury, and progression towards degenerative joint disease in the setting of meniscus deficiency. The purpose of this study was to provide a comprehensive assessment of meniscus tear patterns and repair techniques utilized in children and adolescents to better elucidate features of this common injury and national trends in treatment. Methods: A prospective, multi-center registry of 4 different arthroscopic surgeries—discoid meniscus surgery, non-discoid meniscus repair [medial meniscus repair (MMR) or lateral meniscus tear (LMR)], anterior cruciate ligament reconstruction (ACLR), and tibial spine repair (TSR)—performed by 32 surgeon-investigators at 20 different academic centers over 30 months, was queried for all cases of non-discoid meniscus repair, which were further categorized according to whether they were performed in isolation (I-MR), or in conjunction with ACLR or TSR. Variables collected included patient demographic features (age, sex, BMI), compartment (lateral, LMT; medial, MMT), zone (white-white, red-white, red-red), pattern (longitudinal/vertical, complex/degenerative, radial, oblique/parrot’s beak, horizontal/cleavage), displacement (yes/no), location (anterior, body, posterior, root), repair technique (all-inside, inside-out, outside-in, other), repair implant/construct (menisco-capsular implants/sutures, meniscal-based sutures), and number of implants/sutures. Descriptive statistics and comparative analysis were performed for I-MR vs. ACLR-MR vs. TSR-MR and MMR vs. LMR. Results: Of 1374 meniscus repairs (mean 15.1 years old, range 5-19, 44% Female), 763 (55.5%) were performed for LMT and 611 (44.5%) for MMT, with 184 of all cases (15%) representing bicompartmental meniscus repair (LMR+MMR). ACLR-MR (n=817, 66.9%) was significantly more common than I-MR (n=373, 30.6%), which was significantly more common than TSR-MR (n=31, 2.5%, p=0.001). I-MR had a higher incidence of anterior horn, meniscal body tears, inside out repairs, and outside in repairs (all p<0.001). Of MMTs that underwent repair 81.2% were vertical/longitudinal, while LMTs that underwent repair were comprised of 49.6% vertical/longitudinal, 24.2% complex/degenerative, and 13.9% radial (Table 1). While the most common tear zone for repaired menisci was the red-white zone, 18% of LMR and 13.4% of MMR were in the white-white zone. The posterior horn was one of the most common locations of a repairable lesion (45.1% LMT and 43.9% MMT) with 12.8% of LMT repairs and 6.2% of MMT repairs performed on the posterior root. 70% of repairs were performed with all-inside technique, which was the predominant technique for all tear patterns in both MMT and LMT. Only 14.1% of repairs were performed with inside-out technique, but 70% of these cases were for displaced tears. The average number of implants/sutures for non-displaced tears was 4.0, compared with 5.9 for displaced tears. While a majority of repairs used meniscocapsular repair techniques, 11.1% of meniscus repairs were based on meniscal-based sutures including 20.8% of radial tear repairs. 14 different implants were used by study surgeons (Figures 1 and 2). Conclusions: Amongst tears selected for repair in children and adolescents, LMT is more common than MMT, and the majority of cases arise in conjunction with ACLR, compared to isolated tears. The predominant tear pattern is vertical in MMTs (80%). By percentage, radial tears are seven times more common and posterior root tears are twice as common in lateral meniscus tears. Given the high and increasing frequency of this injury and procedure, nationally, the variation detected in repair techniques and implants utilized represent potential opportunities for optimization of care and reduction in health care costs. [Table: see text]
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Pokhrel, Shiva Raj, Jie Ding, Jihong Park, Ok-Sun Park, and Jinho Choi. "Towards Enabling Critical mMTC: A Review of URLLC Within mMTC." IEEE Access 8 (2020): 131796–813. http://dx.doi.org/10.1109/access.2020.3010271.
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Mäkiaho, Pekka, Katriina Vartiainen, and Timo Poranen. "MMT." International Journal of Human Capital and Information Technology Professionals 8, no. 4 (October 2017): 27–37. http://dx.doi.org/10.4018/ijhcitp.2017100103.
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Hook, Lauren M., Yelena Agafonova, Susan R. Ross, Stephanie J. Turner, and Tatyana V. Golovkina. "Genetics of Mouse Mammary Tumor Virus-Induced Mammary Tumors: Linkage of Tumor Induction to the gagGene." Journal of Virology 74, no. 19 (October 1, 2000): 8876–83. http://dx.doi.org/10.1128/jvi.74.19.8876-8883.2000.
Повний текст джерелаАнотація:
ABSTRACT Retroviruses are believed to induce tumors by acting as insertional mutagens that activate expression of cellular protooncogenes. Indeed, almost 90% of mouse mammary tumor virus (MMTV)-induced mammary tumors in C3H/He mice show upregulation of Int protooncogenes. We have analyzed three different MMTV variants [MMTV(C3H), MMTV(HeJ), and a genetically engineered MMTV hybrid provirus (HP)] for tumorigenicity in mice from two distinct genetic backgrounds. All three viruses were tumor causing in BALB/cJ mice. However, only MMTV(C3H), but not MMTV(HeJ) or HP, induced mammary tumors in C3H/He mice. All of the viruses were infectious on either background and up-regulated expression of Int genes in tumors they induced. Like HP, MMTV(HeJ) was found to be a genetic recombinant between endogenousMtv1 provirus and exogenous MMTV(C3H). Sequence comparison of MMTV variants linked the tumorigenicity of MMTV(C3H) to thegag region of the retrovirus.
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Ando, Y., W. Wajjwalku, N. Niimi, K. Hiromatsu, T. Morishima, and Y. Yoshikai. "Concomitant infection with exogenous mouse mammary tumor virus encoding I-E-dependent superantigen in I-E-negative mouse strain." Journal of Immunology 154, no. 12 (June 15, 1995): 6219–26. http://dx.doi.org/10.4049/jimmunol.154.12.6219.
Повний текст джерелаАнотація:
Abstract We found that milk from II TES mice contained two species of exogenous mouse mammary tumor viruses (MMTV). Sequence analysis of the open reading frame (ORF) in the MMTV 3' long terminal repeat indicated that the two MMTV, MMTV (II TES2) and MMTV (II TES14), encode superantigens specific for V beta 2+ T cells and V beta 14+ T cells, respectively. In an experiment of subcutaneous injection of II TES milk, both T cells bearing TCR V beta 2 and V beta 14 proliferated vigorously in the draining lymph node from BALB/c mice (H-2d I-E+), whereas only V beta 14+ T cells showed significant proliferation in C57BL/6 mouse (B6 H-2b I-E-) lymph nodes. These findings indicated that the superantigen encoded by MMTV (II TES2) required MHC class II I-E molecules exclusively for Ag presentation, but MMTV (II TES14) stimulated V beta 14+ T cells even in the absence of I-E molecules. Semiquantitative analysis of MMTV proviruses using PCR revealed that B6 mice were not infected with MMTV (II TES2) by injection of this MMTV alone. However, injection of II TES milk containing both MMTV (II TES14) and MMTV (II TES2) induced infection of B6 mice with MMTV (II TES2) besides MMTV (II TES14), in spite of no expansion of V beta 2+ T cells in this mouse strain. These results suggested that I-E-negative mice were concomitantly infected with MMTV (II TES2) with the help of I-E independent T cell activation mediated by MMTV (II TES14).
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Lawson, James S., and Wendy K. Glenn. "Mouse Mammary Tumour Virus (MMTV) in Human Breast Cancer—The Value of Bradford Hill Criteria." Viruses 14, no. 4 (March 30, 2022): 721. http://dx.doi.org/10.3390/v14040721.
Повний текст джерелаАнотація:
For many decades, the betaretrovirus, mouse mammary tumour virus (MMTV), has been a causal suspect for human breast cancer. In recent years, substantial new evidence has been developed. Based on this evidence, we hypothesise that MMTV has a causal role. We have used an extended version of the classic A. Bradford Hill causal criteria to assess the evidence. 1. Identification of MMTV in human breast cancers: The MMTV 9.9 kb genome in breast cancer cells has been identified. The MMTV genome in human breast cancer is up to 98% identical to MMTV in mice. 2. Epidemiology: The prevalence of MMTV positive human breast cancer is about 35 to 40% of breast cancers in Western countries and 15 to 20% in China and Japan. 3. Strength of the association between MMTV and human breast cancer: Consistency—MMTV env gene sequences are consistently five-fold higher in human breast cancer as compared to benign and normal breast controls. 4. Temporality (timing) of the association: MMTV has been identified in benign and normal breast tissues up to 10 years before the development of MMTV positive breast cancer in the same patient. 5. Exposure: Exposure of humans to MMTV leads to development of MMTV positive human breast cancer. 6. Experimental evidence: MMTVs can infect human breast cells in culture; MMTV proteins are capable of malignantly transforming normal human breast epithelial cells; MMTV is a likely cause of biliary cirrhosis, which suggests a link between MMTV and the disease in humans. 7. Coherence—analogy: The life cycle and biology of MMTV in humans is almost the same as in experimental and feral mice. 8. MMTV Transmission: MMTV has been identified in human sputum and human milk. Cereals contaminated with mouse fecal material may transmit MMTV. These are potential means of transmission. 9. Biological plausibility: Retroviruses are the established cause of human cancers. Human T cell leukaemia virus type I (HTLV-1) causes adult T cell leukaemia, and human immunodeficiency virus infection (HIV) is associated with lymphoma and Kaposi sarcoma. 10. Oncogenic mechanisms: MMTV oncogenesis in humans probably differs from mice and may involve the enzyme APOBEC3B. Conclusion: In our view, the evidence is compelling that MMTV has a probable causal role in a subset of approximately 40% of human breast cancers.
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Lopez, D. M., V. Charyulu, and R. D. Paul. "B cell subsets in spleens of BALB/c mice: identification and isolation of MMTV-expressing and MMTV-responding subpopulations." Journal of Immunology 134, no. 1 (January 1, 1985): 603–7. http://dx.doi.org/10.4049/jimmunol.134.1.603.
Повний текст джерелаАнотація:
Abstract The DNA of BALB/c mice contains two genomic- and one subgenomic-size MMTV proviruses that appear to be preferentially expressed in their spleen cells, although intact MMTV virions cannot be detected in the tissues of these mice. This retrovirus antigen expression is restricted to a subpopulation of B lymphocytes, as determined by double label immunofluorescence studies. Nylon-adherent, SIg-positive spleen lymphocytes from BALB/c mice are capable of being stimulated by purified MMTV in lymphocyte transformation assays. Two possibilities were explored: the MMTV-positive cells are the responders to MMTV in the blastogenesis assay, or there exists two B lymphocyte subsets, one expressing the MMTV antigen(s) and the other responding to the virus. Depletion of MMTV-positive, nylon-adherent cells with anti-MMTV and complement resulted in no significant change in the blastogenesis to MMTV, indicating that the MMTV-negative lymphocytes are the responders in this reaction. These results were confirmed by positive selection experiments by using a fluorescence-activated cell sorter. Two populations of nylon-adherent cells, on the basis of the presence or absence of MMTV antigen in their surfaces, were obtained by a two-way sorting procedure and were used in lymphocyte transformation assays. MMTV-expressing lymphocytes were found to be nonresponsive to MMTV antigens, although high levels of [3H]thymidine incorporation were observed in the MMTV-negative, nylon-adherent cell cultures exposed to MMTV. These data indicate that in normal BALB/c mice, expression of endogeneous retrovirus genetic information is restricted to a nylon-adherent spleen cell subset that is different from the one responding in blastogenesis to the viral antigens.
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Upragarin, N., H. Nishimura, W. Wajjwalku, Y. Ando, S. Nagafuchi, T. Watanabe, and Y. Yoshikai. "T cells bearing Vbeta8 are preferentially infected with exogenous mouse mammary tumor virus." Journal of Immunology 159, no. 5 (September 1, 1997): 2189–95. http://dx.doi.org/10.4049/jimmunol.159.5.2189.
Повний текст джерелаАнотація:
Abstract We previously reported that a mouse mammary tumor virus (MMTV(II-TES14)), encoding a superantigen specific for TCR Vbeta14, can infect lymph node (LN) cells of mice in an I-E-independent manner. Here we examined the kinetics of cell types infected with exogenous MMTV in the draining LN after s.c. injection of II-TES milk containing MMTV(II-TES14). The infectivity was assessed in LN cells sorted into each cell subset by a semiquantitative analysis of MMTV provirus using PCR with a primer specific for MMTV(II-TES14). Only B cells in the LN were infected by the MMTV on day 6 after injection, but CD8+ T cells and, to a lesser extent, CD4+ T cells were also found to be detectably infected on day 14 after the injection of II-TES milk. Among the T cells we examined, Vbeta8 T cells were most preferentially infected with MMTV, but no Vbeta14 T cells specific for MMTV(II-TES14) superantigen were infected on day 14 after infection. The transfer of Vbeta8 T cells sorted from mice injected with II-TES milk 14 days previously resulted in the deletion of CD4+ Vbeta14 T cells and in the MMTV infection of normal B6 mice. No MMTV infection of T cells occurred in IgM knockout mice, which lack a mature B cell compartment. These results suggest that MMTV surviving in B cells is transferred to Vbeta8 T cells, which may play an important role in MMTV longevity.
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Kang, Bong Gu, June Ho Shin, Jae Kyu Yi, Ho Chul Kang, Jong Joo Lee, Hyen Seok Heo, Ji Hyung Chae, Incheol Shin, and Chul Geun Kim. "Corepressor MMTR/DMAP1 Is Involved in both Histone Deacetylase 1- and TFIIH-Mediated Transcriptional Repression." Molecular and Cellular Biology 27, no. 10 (March 19, 2007): 3578–88. http://dx.doi.org/10.1128/mcb.01808-06.
Повний текст джерелаАнотація:
ABSTRACT A transcription corepressor, MAT1-mediated transcriptional repressor (MMTR), was found in mouse embryonic stem cell lines. MMTR orthologs (DMAP1) are found in a wide variety of life forms from yeasts to humans. MMTR down-regulation in differentiating mouse embryonic stem cells in vitro resulted in activation of many unrelated genes, suggesting its role as a general transcriptional repressor. In luciferase reporter assays, the transcriptional repression activity resided at amino acids 221 to 468. Histone deacetylase 1 (HDAC1) interacts with MMTR both in vitro and in vivo and also interacts with MMTR in the nucleus. Interestingly, MMTR activity was only partially rescued by competition with dominant-negative HDAC1(H141A) or by treatment with an HDAC inhibitor, trichostatin A (TSA). To identify the protein responsible for HDAC1-independent MMTR activity, we performed a yeast two-hybrid screen with the full-length MMTR coding sequence as bait and found MAT1. MAT1 is an assembly/targeting factor for cyclin-dependent kinase-activating kinase which constitutes a subcomplex of TFIIH. The coiled-coil domain in the middle of MAT1 was confirmed to interact with the C-terminal half of MMTR, and the MMTR-mediated transcriptional repression activity was completely restored by MAT1 in the presence of TSA. Moreover, intact MMTR was required to inhibit phosphorylation of the C-terminal domain in the RNA polymerase II largest subunit by TFIIH kinase in vitro. Taken together, these data strongly suggest that MMTR is part of the basic cellular machinery for a wide range of transcriptional regulation via interaction with TFIIH and HDAC.
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Lambert, James R., and Steven K. Nordeen. "CBP Recruitment and Histone Acetylation in Differential Gene Induction by Glucocorticoids and Progestins." Molecular Endocrinology 17, no. 6 (June 1, 2003): 1085–94. http://dx.doi.org/10.1210/me.2001-0183.
Повний текст джерелаАнотація:
Abstract We have analyzed histone acetylation at the steroid-responsive mouse mammary tumor virus (MMTV) promoter in five separate cell lines that express functional glucocorticoid and/or progesterone receptors. Chromatin immunoprecipitation assays reveal that glucocorticoid and progesterone receptors bind the MMTV promoter after hormone addition but that receptor binding is not associated with an increase in acetylation of histone H3 or H4. We have, however, found one exception to this rule. Previously we described a cell line [T47D(C&L)] that displayed a remarkable differential induction of MMTV by glucocorticoids and progestins. At one chromosomal locus (MMTV-luciferase), MMTV is preferentially induced by glucocorticoids, whereas at another locus within the same cell (MMTV-CAT), MMTV is activated by both glucocorticoids and progestins. Here we show that the glucocorticoid-mediated induction of MMTV-luciferase is accompanied by increased recruitment of CBP to the promoter and increased histone H3 and H4 acetylation, whereas the hormonal induction of MMTV-CAT in the same cell exhibits a more modest CBP recruitment without any increase in histone acetylation. These studies suggest that increased histone acetylation may serve a potentiating function for MMTV promoter activation at certain loci. However, increased histone acetylation is not requisite for steroid-mediated induction of transcription at all genes.
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Castex, Marie-Pierre, Hervé Rubie, Michael C. G. Stevens, Carlota Calvo Escribano, Jérôme Sales de Gauzy, Anne Gomez-Brouchet, Annie Rey, Olivier Delattre, and Odile Oberlin. "Extraosseous Localized Ewing Tumors: Improved Outcome With Anthracyclines—The French Society of Pediatric Oncology and International Society of Pediatric Oncology." Journal of Clinical Oncology 25, no. 10 (April 1, 2007): 1176–82. http://dx.doi.org/10.1200/jco.2005.05.0559.
Повний текст джерелаАнотація:
Purpose To evaluate the outcome of children with an extraosseous Ewing tumor (EOE) according to treatment. Patients and Methods Children with EOE were treated either with the strategy used for malignant mesenchymal tumors (MMTs) by the International Society of Pediatric Oncology (SIOP) or with the French Society of Pediatric Oncology (SFOP) regimen used for osseous Ewing tumors (OET). The MMT strategy included vincristine/actinomycin for small and resected tumors or ifosfamide/vincristine/actinomycin for unfavorable sites or unresectable tumors. Surgical excision was to be attempted after four courses, followed by local irradiation in case of residue. Osseous Ewing (OE) protocol included three courses of cyclophosphamide/doxorubicin followed either by two similar courses in case of good response or two courses of ifosfamide/etoposide in case of no response. After resection of the primary, treatment included conventional chemotherapy in case of good histologic response and high-dose chemotherapy and radiotherapy for poor response. All diagnosis specimens were reviewed by the panel. Results Between 1989 and 1999, 63 patients were registered. Characteristics of patients treated by both protocols were similar. Five-year overall survival (OS) and event-free survival (EFS) of those treated with the OE protocol are 83% and 75%, respectively, which is significantly better than the OS and EFS of those treated with the MMT strategy (59% and 44%, respectively; P = .04 and .008, respectively). The size of the primary and the type of protocol influenced patients’ EFS. In multivariate analysis, only the regimen had an impact on OS and EFS. Conclusion Our study shows that patients with EOE should be treated with OE regimens, probably because of the use of anthracyclines.