Academic literature on the topic 'C2 fragment'

This study reports effects of meaning and emotion (taboo vs. neutral words) on an illusory word (IW) phenomenon linked to orthographic repetition blindness (RB). Participants immediately recalled rapid serial visual presentation (RSVP) lists consisting of two critical words (C1 and C2) containing shared letters, followed by a word fragment: for example, lake (C1) brake (C2) ush (fragment). For neutral critical words, participants often recalled C1, but not C2 or the fragment, reporting instead a nonoccurring or illusory word: here, brush (a blend of C2 and the fragment). Forward RB (defined as reduced report of orthographically similar C2s) was more common for neutral than for taboo C2s, and taboo IWs were reported significantly more often than were neutral IWs. Moreover, when both C2 and the potential IW were taboo, a new phenomenon emerged: Participants reliably reported both the IW and the intact C2. These and other results supported a binding theory of the IW phenomenon and orthographic RB.

Abstract Chicken complement factor B-like protease is a glycoprotein of 95 kDa. Activation of chicken serum complement with inulin cleaved the B-like protease into an N-terminal Ba fragment of 37 kDa and a C-terminal Bb fragment of 60 kDa. The whole protein and the two fragments were purified by affinity chromatography using mAb to chicken Ba or Bb followed by ion exchange chromatography. Amino acid sequencing showed that chicken B-like protease was cleaved at a site homologous to that cleaved in mammalian complement components B and C2 on activation. Limited tryptic digestion of the B-like protease generated fragments similar to Ba and Bb. More than 200 residues of the Ba sequence and two N-linked glycosylation sites were established by amino acid sequencing of peptides derived by digestion with four proteases. Comparison of human and mouse C2 and B sequences indicated a slower evolutionary rate for B (85% sequence identity) than for C2 (74% sequence identity). Comparison of chicken Ba to human and mouse C2b and Ba showed 42 to 45% sequence identity with respect to C2b fragments, and 46 to 49% sequence identity with respect to Ba fragments. Taking the slower evolutionary rate of factor B into account, chicken factor B-like protease seems to be equally related to mammalian complement components B and C2, and the B-like protease most likely represents the present-day descendant of a common ancestral protein for mammalian B and C2. This conclusion is in agreement with the requirement for the B-like protease in both classical and alternative activation pathways for chicken complement, and with the apparent lack of a chicken serum protein with exclusive C2 activity.

Photofragmentation investigations were performed by using chromatographically isolated pure samples of higher fullerenes and metallofullerenes. Quite similar distributions of fragments were commonly observed for five different fullerenes, and this fact supports the presence of a “scrambled-cage” structure in a highly excited fullerene cage. An enhancement of the C 60 and C 70 signals was also observed as a result of “delayed C 2-loss” fragmentation within a time scale of about 60 µs after photoexcitation. Photodissociation study of mono- and di-metallofullerenes revealed the qualitative difference in the fragment distributions between them, suggesting that LaC 82 would possess an endohedral, and Sc 2 C 84 an exohedral, form.

A common feature shared by myosin-binding proteins from a wide variety of species is the presence of a variable number of related internal motifs homologous to either the Ig C2 or the fibronectin (Fn) type III repeats. Despite interest in the potential function of these motifs, no group has clearly demonstrated a function for these sequences in muscle, either intra- or extracellularly. We have completed the nucleotide sequence of the fast type isoform of MyBP-C (C protein) from chicken skeletal muscle. The deduced amino acid sequence reveals seven Ig C2 sets and three Fn type III motifs in MyBP-C. alpha-chymotryptic digestion of purified MyBP-C gives rise to four peptides. NH2-terminal sequencing of these peptides allowed us to map the position of each along the primary structure of the protein. The 28-kD peptide contains the NH2-terminal sequence of MyBP-C, including the first C2 repeat. It is followed by two internal peptides, one of 5 kD containing exclusively spacer sequences between the first and second C2 motifs, and a 95-kD fragment containing five C2 domains and three fibronectin type III motifs. The C-terminal sequence of MyBP-C is present in a 14-kD peptide which contains only the last C2 repeat. We examined the binding properties of these fragments to reconstituted (synthetic) myosin filaments. Only the COOH-terminal 14-kD peptide is capable of binding myosin with high affinity. The NH2-terminal 28-kD fragment has no myosin-binding, while the long internal 100-kD peptide shows very weak binding to myosin. We have expressed and purified the 14-kD peptide in Escherichia coli. The recombinant protein exhibits saturable binding to myosin with an affinity comparable to that of the 14-kD fragment obtained by proteolytic digestion (1/2 max binding at approximately 0.5 microM). These results indicate that the binding to myosin filaments is mainly restricted to the last 102 amino acids of MyBP-C. The remainder of the molecule (1,032 amino acids) could interact with titin, MyBP-H (H protein) or thin filament components. A comparison of the highly conserved Ig C2 domains present at the COOH-terminus of five MyBPs thus far sequenced (human slow and fast MyBP-C, human and chicken MyBP-H, and chicken MyBP-C) was used to identify residues unique to these myosin-binding Ig C2 repeats.

Coulomb explosion experiments using linearly polarized intense 60 fs laser pulses were conducted for structural characterization of three dichloroethylene (DCE) isomers, 1,1-DCE, cis-1,2-DCE, and trans-1,2-DCE. Under relatively low laser intensity at 1.8 × 1014 W/cm2, mass-resolved momentum imaging (MRMI) for selected fragment ions of 35Cl+ and C2+ revealed different patterns for the three isomers. The C2+ ion fragmented from multiply charged trans-1,2-DCE was forced to leave perpendicularly to the direction of the laser polarization, due to recoil forces from adjacent cations. In contrast, the fast ions of C2+ from cis-1,2-DCE exhibited an isotropic distribution, whereas the fast ions of C2+ from 1,1-DCE recoiled along the laser polarization together with the slow C2+ ions, and thereby distinction of the three isomers was demonstrated. Coulomb explosion occurs predominantly at specific orientation, which is useful for potential applications of MRMI analysis to molecular structure assays.

Abstract Three miniature swine lines, inbred for swine leukocyte antigen (SLA) haplotypes, a, c, and d, and a recombinant line, haplotype g, were analyzed for possible restriction fragment length polymorphisms (RFLP) by Southern blot hybridization with human C2, factor B (Bf), and C4 specific probes. The search for RFLP by using a human C2 probe failed to reveal any variants. However, a Taq I polymorphism was identified with the human Bf probe and Bam HI and Pvu II polymorphisms were identified with the human C4 probe. Overlapping restriction fragments were found with the C2 and Bf probes, which strongly suggests close linkage of C2 and Bf genes in swine. Segregation analyses of the Bf and C4 polymorphisms indicated that the polymorphic fragments followed a Mendelian pattern of inheritance. The recombinant haplotype g, which expresses class I genes of haplotype c and class II genes of haplotype d, was shown to produce an identical RFLP pattern, by using the Bf and C4 probes, as haplotype d, but different from that of haplotype c. This indicates that there is a close association of [C4-Bf-C2] and class II genes in miniature swine. Although these data do not show conclusively the location of the [C4-Bf-C2] genes, it is hypothesized that swine [C4-Bf-C2] genes are located between the class II and class I genes, as has been demonstrated in mouse and man.

An AO type C2 distal radius fracture was simulated in a cadaver model by creating a metaphyseal defect of 5 mm and an intra-articular defect of 2 mm. Five different methods of plate osteosynthesis were tested biomechanically in each of six fresh cadaveric hands. Biomechanical testing suggested that cement augmented plating plus screws in the distal fragment was the strongest. Dorsal and volar plating plus screws on both sides of the distal fragment had the same effect of restoring stiffness and load transmission pattern as fixation with double plating plus volar screws alone. Fixation with plating plus dorsal screws was significantly weaker than these three methods, and double buttress plating with no screws in the distal fragments was the weakest.

Monkeypox is a serious public health issue in tropical and subtropical areas. Antivirals that target monkeypox proteins might lead to more effective and efficient therapy. The F13 protein is essential for the growth and maturation of the monkeypox virus. F13 inhibition might be a viable therapeutic target for monkeypox. The in silico fragment-based drug discovery method for developing antivirals may provide novel therapeutic options. In this study, we generated 800 compounds based on tecovirimat, an FDA-approved drug that is efficacious at nanomolar quantities against monkeypox. These compounds were evaluated to identify the most promising fragments based on binding affinity and pharmacological characteristics. The top hits from the chemical screening were docked into the active site of the F13 protein. Molecular dynamics simulations were performed on the top two probable new candidates from molecular docking. The ligand–enzyme interaction analysis revealed that the C2 ligand had lower binding free energy than the standard ligand tecovirimat. Water bridges, among other interactions, were shown to stabilize the C2 molecule. Conformational transitions and secondary structure changes in F13 protein upon C2 binding show more native three-dimensional folding of the protein. Prediction of pharmacological properties revealed that compound C2 may be promising as a drug candidate for monkeypox fever. However, additional in vitro and in vivo testing is required for validation.

Abstract We raised murine mAb against human C protein C2. The representative mAb 3A3.3 (IgG1 kappa) recognized an epitope on the C2b domain of C2, as determined by binding and inhibition of binding radioassays. The hemolytic activity of purified human C2 and of C2 in normal human serum was inhibited by the mAb. The rate of decay of the C3-convertase at 30 degrees C was not affected by the mAb. C2 binding to EAC4b was inhibited by intact IgG and the Fab fragment of the mAb; 50% inhibition required 1 microgram/ml of either. The data suggest the presence of a C4b-binding site on the C2b domain of C2 and that the mAb recognizes an epitope at, or adjacent to, this site. The C2b portion of the C2 molecule may be important in assembly of the classical pathway C3-convertase.

Neisseria meningitidis is the major cause of meningitis and sepsis, two kind of diseases that can affect children and young adults within a few hours, unless a rapid antibiotic therapy is provided. The meningococcal disease dates back to the 16th century. The first description of the disease caused by this pathogen was stated by Viesseux in 1805 as 33 deaths occurred in Geneva, Switzerland [1]. It took about seventy years before two Italians (Marchiafava and Celli) in 1884 identified micrococcal infiltrates within the cerebrospinal fluid [2]. The worldwide presence of meningococcal serogroups may vary within regions and countries. With the coming of antimicrobial agents, like sulphonamides, and with the development of an appropriate health care and prevention programme, the fatality rate cases has dropped from 14% to 9%, although 11% to 19% of patients continued to have post-infection issues such as neurological disorders, hearing or limb loss [3]. The bacteria can be divided into 13 different serogroups and, among these, up to 99% of infection is ascribed to the serogroups named A, B, C, 29E, W-135 and Y (Fig. 2). All the serogroups have been listed in 20 serotypes on the presence of PorB antigen, 10 serotypes on the presence of PorA antigen, and in other immunotypes on the presence of other bacterial proteins and on the presence of a characteristic lipopolysaccharide called LOS (lipooligosaccharide) [4]. The transmission from a carrier to an other person occurs by liquid droplet and the natural reservoir of Neisseria meningitidis is the human throat, in particular it usually invades the human nasopharynx where it can survive asymptomatically. The reported annual incidence goes from 1 to 5 cases per 100000 inhabitants in industrialized countries, while in non developed-countries the incidence goes up to 50 cases per 100000 inhabitants. More then 50% of cases occur within children below 5 years of age, and the peak regards those under the first year of age. This fact is due to the loss of maternal antibodies by the newborn. In non-epidemic period, the percentage of healthy carriers range from 10 to 20%, and notably the condition of chronic carrier is not so uncommon [5, 6]. Only in a small percentage of cases the colonization progresses until the insurgence of the pathogenesis. This happens because in the majority of cases specific antibodies or the human complement system are able to destroy the pathogens in the blood flow allowing a powerful impairment of the dissemination. In a small group of population the colonization of the upper respiratory tract is followed by a rapid invasion of the epithelial cells, and from there bacteria can reach the blood flow and invade the central nervous system (CNS), inducing the establishment of an acute inflammatory response. How the balance between being an healthy carrier or a infected patient can change so rapidly it is still unknown. Some factors that can play a role in this switch could be the virulence of the bacterial strain, the responsiveness of the host immune system, the mucosal integrity, and some environmental factors [7]. Neisserial heparin binding antigen (NHBA) is a surface- exposed lipoprotein from Neisseria meningitidis that was originally identified by reverse vaccinology [8]. NHBA in Nm has a predicted molecular weight of 51 kDa. The protein contains an Arg-rich region (-RFRRSARSRRS-) located at position 296–305 that is highly conserved among different Nm strains. The protein is specific for Neisseria species, as no homologous proteins were found in non redundant prokaryotic databases. Full length NHBA can be cleaved by two different proteases in two different manners: NalP, a neisserial protein with serine protease activity cleaves the entire protein at its C-terminal producing a 22 kDa protein fragment (commonly named C2) which starts with Ser293 and hence comprises the highly conserved Arg-rich region. The human proteases lactoferrin (hLf) cleaves NHBA immediately downstream of the Arg-rich region releasing a shorter fragment of approximately 21 kDa (commonly named C1) [9] . Although it is known that a crucial step in the pathogenesis of bacterial meningitidis is the disturbance of cerebral microvascular endothelial function, resulting in blood-brain barrier breakdown, the bacterial factor(s) produced by Nm responsible for this alteration remains to be established. The integrity of the endothelia is controlled by the protein VE-cadherin, mainly localized at cell-to-cell adherens junctions where it promotes cell adhesion and controls endothelial permeability [10]. It has been reported that alteration in the endothelial permeability can be ascribed to phosphorylation events induced by soluble factors such as VEGF or TGF-beta[11] [12]. Our work demonstrates that the NHBA- derived fragment C2 (but not C1) increases the endothelial permeability of HBMEC (human brain microvasculature endothelial cells) grown as monolayer onto the membrane of a transwell system. Indeed, the exposure of the apical domain of the endothelium to C2 allows the passage of the fluorescent tracer BSA-FITC, from the apical side to the basal one, early after the treatment. Interestingly, the effect of C2 on the endothelium integrity is such to allow the passage of bacteria, E. coli but, notably, also N. meningitidis MC58, from the apical to the basolateral side of the transwell and it depends on the production of mitochondrial ROS. Remarkably, we have found that the administration of C2 to endothelia results in a ROS-dependent reduction of the total VE-cadherin content. This event requires after VE-cadherin phosphorylation, the endocytosis and the subsequent degradation of the protein. Collectively our data suggest the possibility that C2 might be involved in the mechanisms of invasion owned by the bacterium to cross host tissues.
Neisseria meningitidis è uno dei patogeni in grado di causare meningite oltre che sepsi in soggetti infettati, due patologie che colpiscono maggiormente bambini e adolescenti entro poche ore dal contagio a meno di una tempestiva terapia antibiotica. La malattia meningococcica risale al sedicesimo secolo. La prima descrizione della malattia causata da questo agente patogeno avvenne ad opera di Viesseux nel 1805 come conseguenza di 33 decessi occorsi a Ginevra, Svizzera [1]. Circa 70 anni dopo, due italiani (Marchiafava e Celli) nel 1884 identificarono per la prima volta degli infiltrati meningococcichi nel fluido cerebrospinale [2]. La presenza di Neisseria meningitidis nel mondo varia in base a paesi e regioni e risulta essere ciclica. Grazie alla scoperta di agenti antimicrobicidi come i sulfonamidici e grazie alla diffusione di un adeguato protocollo di prevenzione sanitaria i casi di mortalita` dovuti a questo agente patogeno sono rapidamente diminuiti dal 14 al 9%. Ciò nonostante una percentuale compresa tra l’11 e il 19% dei soggetti ha continuato ad avere problemi post-infezione come disordini neurologici, o perdità dell’udito [3]. Esistono attualmente 13 sierogruppi e, di questi, il 99% delle infezioni è causato dai tipi A, B, C, 29E, W-135 e Y. I sierogruppi sono stati a loro volta classificati in 20 sierotipi sulla base della presenza dell’antigene proteico PorB, in 10 sierotipi sulla base dell’antigene PorA e in altri immunotipi a seconda della loro capacita` di indurre una risposta immunitaria nell’ospite grazie alla presenza di altre proteine batteriche del patogeno, e per la presenza di un particolare lipopolisaccaride chiamato LOS (lipooligosaccaride) [4]. Neisseria meningitidis è in grado di colonizzare l’epitelio della mucosa orofaringea, dove vi può sopravvivere in maniera asintomatica per l’ospite. La trasmissione inter-individuale avviene attraverso secrezioni dell’apparato respiratorio. L’ incidenza annuale risulta essere di 1- 5 casi ogni 100000 abitanti nei paesi industrializzati, mentre nei paesi ancora in via di sviluppo questa sale a 50 casi per 100000 abitanti. Più del 50% dei casi riguarda bambini sotto i 5 anni d’età, con un’elevata incidenza per coloro che hanno meno di un anno di vita. Questo fatto dipende dall’emivita degli anticorpi materni solitamente in grado di proteggere il neonato per circa 3-4 mesi dopo la nascita. In periodi definiti non-epidemici la percentuale dei portatori sani varia tra il 10 e il 20% della popolazione, e per l’appunto la condizione di portatore asintomatico non è poi così infrequente [5, 6]. Soltanto in un numero ristretto di casi la colonizzazione del batterio progredisce manifestando la patogenesi meningococcica: ciò è per la maggior parte dovuto alla presenza di specifici anticorpi, o per l’attività del sistema del complemento dell’ospite che è in grado di controllare ed eliminare il patogeno impedendone così la sua disseminazione attraverso il flusso sanguigno. Tuttavia, in un piccolo gruppo della popolazione, la colonizzazione del tratto respiratorio superiore è seguita da una rapida invasione delle cellule epiteliali della mucosa, da dove il batterio è in grado di entrare nel torrente ematico, e raggiungere il sistema nervoso centrale inducendo una forte risposta infiammatoria. Quale sia l’evento che perturbi l’equilibrio tra essere portatore asintomatico e paziente infetto ancora non è noto. Alcuni fattori sembrano giocare un ruolo chiave in questo cambiamento come la virulenza del ceppo batterico, la capacità della risposta immunitaria dell’ospite, l’integrità della mucosa e alcuni fattori ambientali [7]. La proteina NHBA, Neisserial Heparin Binding Antigen, è una lipoproteina esposta sulla superficie del batterio, originariamente identificata attraverso la tecnica della “reverse vaccinology” [8]. NHBA in Nm ha un peso molecolare predetto di 51 kDa. La proteina altresì contiene una regione ricca in Arginine (-RFRRSARSRRS-) localizzata in posizione 296 -305 ed altamente conservata in vari ceppi di Neisseria [9]. Tale proteina è altamente conservata in Neisseria e non ha omologie di sequenza con nessun’altra proteina registrata nei database procariotici. Due diverse proteasi possono tagliare la proteina intera NHBA producendo due frammenti differenti: nel primo caso la proteasi batterica NalP taglia la proteina intera in posizione C-terminale producendo un frammento di 22 kDa (comunemente chiamato C2) che inzia con la Ser293 e quindi comprendendo lo stretch di Arginine. Invece, nel secondo caso, la lattoferrina umana (hLf) taglia NHBA immediatamente a monte della sequenza di Arginine, producendo un frammento più corto di circa 21 kDa (comunemente chiamato C1). Sebbene sia risaputo che un passaggio cruciale nella patogenesi mediata da Neisseria meningitidis sia l’alterazione della funzione di barriera della microvascolatura encefalica, che può dunque risultare in una rottura della barriera emato- encefalica stessa, non è ancora chiaro quali siano i fattori rilasciati o prodotti dal batterio in grado di indurre un simile effetto. L’integrità dell’endotelio è controllata dalla proteina VE-caderina, localizzata sulle giunzioni aderenti che regolano il contatto cellula- cellula. Tale proteina promuove e regola dunque la permeabilità endoteliale [10]. E’ stato ben documentato che l’alterazione della permeabilità endoteliale può essere dovuta a processi di fosforilazione indotti da fattori solubili come VEGF o TGF-beta[11] [12]. Il nostro lavoro documenta come, a differenza del frammento C1, il frammento C2 prodotto dal taglio della proteina intera NHBA, sia in grado di aumentare la permeabilità delle cellule endoteliali HBMEC (human brain microvasculature endothelial cells) fatte crescere a monostrato sulla membrana di un sistema di transwell. L’esposizione della porzione apicale dell’endotelio polarizzato al frammento C2 consente il passaggio di un tracciante fluorescente, BSA-FITC, dal lato superiore a quello inferiore del transwell, in tempi rapidi a seguito del trattamento. E’ interessante notare che l’effetto di C2 sull’endotelio è tale da permettere il passaggio dal lato superiore a quello inferiore del transwell non solo di E. coli, usato come modello batterico preliminare, ma anche dello stesso Neisseria meningitidis MC58, in maniera ROS dipendente. Degno di nota è il fatto che abbiamo osservato che la somministrazione di C2 alle cellule endoteliali provoca una riduzione ROS dipendente del contenuto totale di VE-caderina. A seguito della sua fosforilazione, infatti, VE-caderina viene endocitata all’interno della cellula per poi essere degradata probabilmente attraverso il trasporto di essa verso il proteasoma. I nostri dati suggeriscono pertanto che C2 sia uno dei meccanismi di invasione possieduti da Neisseria per invadere i tessuti dell'ospite.

Les effets du dérèglement de l’expression des protéines kinases DYRK (Dual-specificity tyrosine phosphorylation-regulated kinase) et plus particulièrement de DYRK1A sont étudiées dans le cas des maladies neurodégénératives (maladie d’Alzheimer, syndrome de Down) et celui de certains cancers. Ces travaux de thèse s’inscrivent dans la continuité des acquis du laboratoire et des résultats des évaluations de l’activité inhibitrice obtenus sur les thiazolo[5,4-f]quinazolines et les thiazolo[5,4-f]quinazolin-9(8H)-ones. L’objectif principal est la modulation du groupement en position C2 des thiazolo[5,4-f]quinazolin-9(8H)-ones en faisant varier la taille et la nature des substituants afin de former des inhibiteurs potentiels sélectifs de DYRK1A. Le premier chapitre de ce manuscrit concerne l’addition de nucléophiles originaux tels que des acides aminés sur la fonction nitrile en position C2 de la 8-benzylthiazolo[5,4-f]quinazolin-9(8H)-one. Le second chapitre décrit l’optimisation de la synthèse des thiazolo[5,4-f]quinazolin-9(8H)-ones ainsi que l’arylation directe ces motifs. La réaction de débenzylation des dérivés C2-arylés et la fonctionnalisation par C–H alcénylation de la 8-benzylthiazolo[5,4-f]quinazolin-9(8H)-one sont aussi décrites dans cette partie. Le troisième chapitre concerne l’évaluation de l’activité biologique de la plupart des composés synthétisés au cours de ces travaux, révélant le FC162 en tant qu’inhibiteur de DYRK1A. Ces résultats ont conduit à la modulation en position C2 de motifs plus simples : les benzo[d]thiazoles, permettant d’étudier la régiosélectivité du 6-aminobenzo[d]thiazole-2,7-dicarbonitrile et l’arylation directe de ces dérivés bicycliques
The effects of expression modulation of protein kinases DYRK (Dual-specificity tyrosine phosphorylation-regulated kinase) and especially of DYRK1A are characterized in a variety of diseases including neurodegenerative diseases (Alzheimer’s disease or Down syndrome) and cancers. This thesis deals with our laboratory knowledge and previous results obtained with thiazolo[5,4-f]quinazolines and thiazolo[5,4-f]quinazolin-9(8H)-ones and their activity. The main part of this thesis is focused on the C2-modulation of thiazolo[5,4-f]quinazolin-9(8H)-ones to synthesize potent DYRK1A inhibitors. The first chapter of this manuscript describes the addition of nucleophiles such as amino acids at the C2-function of 8-benzylthiazolo[5,4-f]quinazolin-9(8H)-ones. The second chapter is focused on the optimization of the thiazolo[5,4-f]quinazolin-9(8H)-ones synthesis and their C–H arylation. Deprotection of C2-arylated products and C–H alkenylation approach of 8-benzylthiazolo[5,4-f]quinazolin-9(8H)-one are also described. The third chapter deals with the inhibitory activity evaluation of most of the compounds prepared along this work shown FC162 as DYRK1A inhibitor. These results led to C2 modulation of simpler structures such as benzo[d]thiazoles by studying the C–H arylation of these bicyclic derivatives

Neisserial Heparin Binding Antigen (NHBA) is a surface-exposed lipoprotein specific for Neisseria and is one of the three main protein antigens of the Bexsero vaccine. Meningococcal and human proteases, including lactoferrin and kallikrein, cleave NHBA protein upstream or downstream a conserved Arg-rich motif, respectively. The cleavage results in the release of the C-terminal portion of the protein. C-terminal fragment originating from the processing of meningococcal proteases, referred as C2 fragment, exerts a toxic effect on endothelial cells altering their permeability. In this work, we reported that recombinant C2 fragment has no influence on the integrity of human airway epithelial cell monolayers, consistently with previous findings showing that N. meningitidis traverses the epithelial barrier without disrupting the junctional structures. Unexpectedly, epithelial cells constantly secreted proteases responsible for a rapid processing of C2 fragment, generating a new fragment that does not contain the Arg-rich motif. This cleavage might inactivate the toxic effect of C2 fragment by eliminating its docking domain. Epithelial cell proteases processed also the NHBA full-length protein, and we demonstrated it on live bacteria. Moreover, looking for the epithelial cell protease responsible for this processing, we identified the C3-convertase of alternative complement pathway as a novel human protease able to cleave NHBA during meningococcal infection. Overall, our data provide new insights on the cleavage of NHBA protein during meningococcal infection. This cleavage occurs at different stages of the infection, and it likely has a different role depending on the environment the bacterium is interacting with.

The excavations (which encompassed 6.2 ares) and surface surveys carried out to date allow the chronology of the cemetery to be determined as spanning from phases A3 of the Younger Pre-Roman period to phase C1b/C2 of the Roman period. The cemetery in Żelazna Nowa was established in phase A3 and remained in uninterrupted use until phase C1b (C2?). Due to significant damage and the small number of artefacts being good chronological indicators, only some of the graves could be dated. The earliest phase is represented by a small group of graves discovered in the north-western part of the site and dated to phase A3. Their chronology was determined based on ceramic vessels, three N brooches. Phase B1 is well-discernible in the materials, especially in the north-western part of the necropolis. A concentration of interesting artefacts, including imports, was found in this area during surface surveys: two brass brooches of the A.67a type, two decorative figure-of-eight fittings made from lead brass, and a brass bracelet of the Kamieńczyk type. Phase B2 is the most well-represented phase in the site. Burials from that phase occupy the central part of the explored area, and they include the quadrangular groove feature with three graves and a number of other graves, mainly urned cremations, discovered over a small area. The late phase of the necropolis is only discernible in uncontexted finds: fragments of wheel-made vessels and two bows of tendril brooches.

Von Willebrand Factor (VWF) is a multimeric plasma glycoprotein that mediates platelet adhesion and aggregation, a process critical for both hemostasis and thrombosis. Under normal conditions, VWF binds to platelets at sites of vascular injury or damage, leading to blood clot formation and wound healing. VWF contains four types of repeating domains in the following sequence: D1-D2-D’-D3-A1-A2-A3-D4-B1-B2-B3-C1-C2-CK (CK: cystine knot). It is synthesized and secreted into plasma by endothelial cells and megakaryocytes. Many newly-secreted VWF multimers are huge in size, thus they are termed ultra-large VWF (ULVWF). ULVWF is thrombogenic, so it is reduced to smaller VWF multimers by ADAMTS13, a metalloprotease that cleaves the Tyr1605-Met1606 bond in the A2 domain of VWF. Proper ULVWF cleavage and subsequent VWF cleavage result in appropriate size distribution of VWF in plasma, which is required for its hemostatic function. On the one hand, insufficient cleavage of ULVWF leads to thrombotic thrombocytopenic purpura (TTP), a disease characterized by microvascular thrombosis; on the other hand, excessive cleavage of VWF leads to Von Willebrand disease (VWD), a potentially-fatal bleeding disorder manifested by lack of large VWF multimers in plasma [1]. Therefore, understanding VWF cleavage by ADAMTS13 is crucial for understanding VWF function and its related diseases.

We consider the problem of learning generalized policies for classical planning domains using graph neural networks from small instances represented in lifted STRIPS. The problem has been considered before but the proposed neural architectures are complex and the results are often mixed. In this work, we use a simple and general GNN architecture and aim at obtaining crisp experimental results and a deeper understanding: either the policy greedy in the learned value function achieves close to 100% generalization over instances larger than those used in training, or the failure must be understood, and possibly fixed, logically. For this, we exploit the relation established between the expressive power of GNNs and the C2 fragment of first-order logic (namely, FOL with 2 variables and counting quantifiers). We find for example that domains with general policies that require more expressive features can be solved with GNNs once the states are extended with suitable "derived atoms" encoding role compositions and transitive closures that do not fit into C2. The work follows an existing approach based on GNNs for learning optimal general policies in a supervised fashion, but the learned policies are no longer required to be optimal (which expands the scope, as many planning domains do not have general optimal policies) and are learned without supervision. Interestingly, value-based reinforcement learning methods that aim to produce optimal policies, do not always yield policies that generalize, as the goals of optimality and generality are in conflict in domains where optimal planning is NP-hard.

Cibulakan Formation as one of the prolific hydrocarbon-bearing intervals has become an interesting study object for many researchers. The continuous outcrop of the Cibulakan Formation in the Cipamingkis River comprises claystone, sandstone, and subordinate limestone of grainstone, packstone, and wackestone facies. The outcrop should be able to give a clearer vertical and spatial variation of sandstone and limestone geometry compared to the conventional core alone. Field observations followed by measuring the section is conducted to distinguish lithofacies and to create a stratigraphic profile from the chosen interval. Samples and thin sections from sandstone and limestone lithofacies are observed further to determine fragment type variation, matrix, cement, texture, and porosity types qualitatively. Fourteen (14) lithofacies have been recognized from the observation, i.e., Slumped Sandstone (A1), Claystone (A2), Slightly-bioturbated Sandstone (B1), Cross-laminated Sandstone (B2), Parallel-laminated Siltstone (B3), Calcareous Claystone (B4), Moderately-bioturbated Sandstone (C1), Hummocky Cross-stratified Sandstone (C2), Skeletal – Coral clast Wackestone (C3), Skeletal-clast Packstone (C4), Coralline Foraminiferal Boundstone (C5), Low-angle Planar Cross-bedded Sandstone (D1), Intensely-bioturbated Sandstone (D2), and Trough Cross-bedded Sandstone (D3). There are four architectural facies in the research interval and each of them is composed of different and specific lithofacies. An ideal parasequence is composed of all Architectural Facies namely : (A) Offshore-Transition (B) Lower Shoreface (C) Upper Shoreface with the whole thickness range between 15 to 25 m and the parasequence shows thickening upward succession. The detailed information about the lithofacies and architectural facies hopefully will provide a better understanding of the facies modelling of the mixed carbonate-siliciclastic depositional setting, new insights for parasequence recognition in clastic shoreline depositional environment and become a reference for other areas lacking in core data and/or outcrop analogue.