[Research progress on the role of resveratrol in wound healing]

The difficulty of wound healing in patients is a difficult problem that doctors in all clinical departments may encounter, and there is still no good solution. Resveratrol is a kind of natural active substance, which has anti-inflammatory, antioxidant, antibacterial, and angiogenesis promoting effects, and is a potential drug to promote wound healing. However, the clinical application of resveratrol is limited due to its low bioavailability. In this review, the molecular mechanism of resveratrol in promoting wound healing and its administration methods in wound treatment were reviewed to provide ideas for the redevelopment of resveratrol.

[Research progress on HEG1 in cardiovascular generation and tumor development]

Heart development protein with EGF-like domains 1 (HEG1) is a novel mucin-like membrane protein with a long O-glycosylation region and EGF domain. HEG1 plays critical roles in embryo development and cardiogenesis, and is closely related to the occurrence and progression of malignant tumors. Here this article demonstrates the research progress on HEG1 in cardiovascular formation and tumor development in recent years, to inspire new ideas for the pathogenesis, diagnosis and treatment of related diseases.

[Progress and reflection of conversion therapy for locally advanced pancreatic cancer]

With the improvement of nonsurgical treatment in pancreatic cancer, the increasing accuracy of subclassification of anatomy, and the continuous refinement of surgical resection techniques, more and more locally advanced pancreatic cancer(LAPC) patients have the opportunity to undergo conversion surgery and achieve survival benefits,which has attracted the attention of scholars in this field. Despite the numerous prospective clinical studies conducted, there is still a lack of high-level evidence-based medical evidence in terms of conversion treatment strategies, efficacy evaluation, surgical timing and survival prognosis, and there are not yet specific quantitative standards and guiding principles for conversion treatment for these patients in clinical practice, and the indications for surgical resection rely more on the experience of each center or surgeon, lacking consistency. Therefore,the indicators for the evaluation of the efficacy of conversion treatment in patients with LAPC were summarized to reflect on the different modes of conversion treatment and clinical outcomes currently being explored, expecting to provide more accurate recommendations and guidance for the clinic.

[Population structure of food-borne Staphylococcus aureus in China]

Objective: To understand the population structure of food-borne Staphylococcus (S.) aureus in China. Methods: Whole genome sequencing was used to analyze 763 food-borne S. aureus strains from 16 provinces in China from 2006 to 2020. Multilocus sequence typing (MLST), staphylococcal protein A gene (spa) typing, and staphylococcal chromosome cassettemec (SCCmec) typing were conducted, and minimum spanning tree based on ST types (STs) was constructed by BioNumerics 7.5 software. Thirty-one S. aureus strains isolated from imported food products were also included in constructing the genome phylogenetic tree. Results: A total of 90 STs (20 novel types) and 160 spa types were detected in the 763 S. aureus isolates. The 72 STs (72/90, 80.0%) were related to 22 clone complexes. The predominant clone complexes were CC7, CC1, CC5, CC398, CC188, CC59, CC6, CC88, CC15, and CC25, accounting for 82.44% (629/763) of the total. The STs and spa types in the predominant clone complexes changed over the years. The methicillin-resistant S. aureus (MRSA) detection rate was 7.60%, and 7 SCCmec types were identified. The ST59-t437-Ⅳa (17.24%, 10/58), ST239-t030-Ⅲ (12.07%, 7/58), ST59-t437-Ⅴb (8.62%, 5/58), ST338-t437-Ⅴb (6.90%, 4/58) and ST338-t441-Ⅴb (6.90%, 4/58) were the main types in MRSA strains. The genome phylogenetic tree had two clades, and the strains with the same CC, ST, and spa types clustered together. All CC7 methicillin sensitive S. aureus strains were included in Clade1, while 21 clone complexes and all MRSA strains were in Clade2. The MRSA strains clustered according to the SCCmec and STs. The strains from imported food products in CC398, CC7, CC30, CC12, and CC188 had far distances from Chinese strains in the tree. Conclusions: In this study, the predominant clone complexes of food-borne strains were CC7, CC1, CC5, CC398, CC188, CC59, CC6, CC88, CC15, and CC25, which overlapped with the previously reported clone complexes of hospital and community-associated strains in China, suggesting that close attention needs to be paid to food, a vehicle of pathogen transmission in community and food poisoning.

[Study of the urban-impact on microbial communities and their virulence factors and antibiotic resistance genomes in the Nandu River, Haikou]

Objective: To explore the changes in bacterial community structure, antibiotic resistance genome, and pathogen virulence genome in river water before and after the river flowing through Haikou City and their transmission and dispersal patterns and to reveal anthropogenic disturbance's effects on microorganisms and resistance genes in the aquatic environment. Methods: The Nandu River was divided into three study areas: the front, middle and rear sections from the upstream before it flowed through Haikou City to the estuary. Three sampling sites were selected in each area, and six copies of the sample were collected in parallel at each site and mixed for 3 L per sample. Microbial community structure, antibiotic resistance, virulence factors, and mobile genetic elements were analyzed through bioinformatic data obtained by metagenomic sequencing and full-length sequencing of 16S rRNA genes. Variations in the distribution of bacterial communities between samples and correlation of transmission patterns were analyzed by principal co-ordinates analysis, procrustes analysis, and Mantel test. Results: As the river flowed through Haikou City, microbes' alpha diversity gradually decreased. Among them, Proteobacteria dominates in the bacterial community in the front, middle, and rear sections, and the relative abundance of Proteobacteria in the middle and rear sections was higher than that in the front segment. The diversity and abundance of antibiotic resistance genes, virulence factors, and mobile genetic elements were all at low levels in the front section and all increased significantly after flow through Haikou City. At the same time, horizontal transmission mediated by mobile genetic elements played a more significant role in the spread of antibiotic-resistance genes and virulence factors. Conclusions: Urbanization significantly impacts river bacteria and the resistance genes, virulence factors, and mobile genetic elements they carry. The Nandu River in Haikou flows through the city, receiving antibiotic-resistant and pathogen-associated bacteria excreted by the population. In contrast, antibiotic-resistant genes and virulence factors are enriched in bacteria, which indicates a threat to environmental health and public health. Comparison of river microbiomes and antibiotic resistance genomes before and after flow through cities is a valuable early warning indicator for monitoring the spread of antibiotic resistance.

Speaking the host language: how Salmonella effector proteins manipulate the host

Salmonella injects over 40 virulence factors, termed effectors, into host cells to subvert diverse host cellular processes. Of these 40 Salmonella effectors, at least 25 have been described as mediating eukaryotic-like, biochemical post-translational modifications (PTMs) of host proteins, altering the outcome of infection. The downstream changes mediated by an effector's enzymatic activity range from highly specific to multifunctional, and altogether their combined action impacts the function of an impressive array of host cellular processes, including signal transduction, membrane trafficking, and both innate and adaptive immune responses. Salmonella and related Gram-negative pathogens have been a rich resource for the discovery of unique enzymatic activities, expanding our understanding of host signalling networks, bacterial pathogenesis as well as basic biochemistry. In this review, we provide an up-to-date assessment of host manipulation mediated by the Salmonella type III secretion system injectosome, exploring the cellular effects of diverse effector activities with a particular focus on PTMs and the implications for infection outcomes. We also highlight activities and functions of numerous effectors that remain poorly characterized.

[Risk assessment of Cronobacter sakazakii in infant formula powder]

Objective: To assess the risk of foodborne diseases caused by Cronobacter sakazakii in infant formula powder from retail to feeding and provide formulate suggestions for safe feeding of infants at home. Methods: This study used the special monitoring and risk monitoring data of infant formula powder in Heilongjiang Province and combined data at home and abroad. The @RISK software was used to evaluate the disease risk caused by Cronobacter sakazakii in the process of infant formula powder from retail to feeding. Results: According to the results of this quantitative risk assessment, the risk of foodborne diseases caused by Cronobacter sakazakii at the current consumption pattern in Heilongjiang Province was 5.158×10^-5 persons/million (40.0 ℃ and 50.0 ℃), 1.072×10^-7 persons/million (60.0 ℃), 5.544×10^-14 persons/million (70.0 ℃). When the feeding time of infant formula powder was adjusted to 0-2 h and 2-3 h respectively, the above prediction results did not change. When it was adjusted to 3-4 h, the risk increased. If it was adjusted to 4-24 h, the number of Cronobacter sakazakii increased by 14-24 orders of magnitude at room temperature. If the initial pollution concentration (after flushing) was adjusted to 1 MPN/ml, the average disease risk per meal was 805.7 persons/million (40.0 ℃ and 50.0 ℃), 1.7 persons/million (60.0 ℃) and 9.1 × 10^-7 persons/million (70.0 ℃). The results of sensitivity analysis showed that the water temperature (70.0 ℃), initial pollution concentration, room storage time and temperature were important factors of risk. Conclusion: Controlling the contamination level of Cronobacter sakazakii in infant formula powder, controlling the feeding time within 3 h, storing in refrigerator and mixing with water with temperature not lower than 70.0 ℃ are effective measures to prevent infants from eating infant formula powder infected by Cronobacter sakazakii.

[Changes of brain network characteristics in patients with depression before and after precise repetitive transcranial magnetic stimulation]

Objective: To investigate the changes of brain network characteristics in patients with depression before and after precise repetitive transcranial magnetic stimulation (rTMS) treatment. Methods: Patients with depression in the Second Affiliated Hospital of Xinxiang Medical University and healthy volunteers in the community of Xinxiang city from February 2018 to March 2019 were simultaneously recruited. The left dorsolateral prefrontal cortex was precisely selected as the stimulation target through the latest Human Brainnetome Atlas, and the near infrared navigation was used to achieve accurate brain stimulation treatment in combination with the structural magnetic resonance data. Moreover, functional connectivity was analyzed before and after rTMS treatment in significantly altered brain areas of patients with depression. Results: Nineteen patients (11 males and 8 females) with depression were included, aged (34±11) years. Meanwhile, 22 healthy controls (9 males and 13 females), aged (30±9) years, were also enrolled. Functional connectivity of insular cortex was decreased in depression patients when the insula was analyzed as the target area (P<0.05). The functional connection from insula to middle frontal lobe and superior parietal lobe in patients with depression decreased before rTMS treatment (P<0.05), but increased after rTMS treatment (P<0.05). The functional connection between dIg_L of the insula and the right middle prefrontal lobe was correlated with Beck Anxiety Index (BAI) before rTMS treatment and Beck Depression Index (BDI) after rTMS treatment (r=0.737, P=0.003; r=0.696, P=0.005). Conclusions: Abnormal functional connectivity of insula may be the brain imaging mechanism of rTMS treatment. Precise brain region selection based on Human Brainnetome Atlas provides a new technical method for clinical rTMS precision treatment.

[Minimally invasive enucleation for benign and low-grade malignant pancreatic tumors: an analysis of 60 cases]

Objective: To investigate the safety and feasibility of minimally invasive pancreatic tumor enucleation. Methods: The clinicopathological data of 60 patients with minimally invasive pancreatic tumor enucleation admitted to the Department of Pancreatic Surgery of Fudan University Cancer Center from November 2019 to August 2021 were retrospectively analyzed. There were 17 males and 43 females,with age of (50.0±13.2)years(range: 23 to 73 years). Tumors were located in the head of pancreas in 40 cases(66.7%),neck and tail of pancreas in 20 cases(33.3%). Patients were divided into robotic group(n=25) and laparoscopic group(n=35) according to surgical methods. The measurement data were compared by t-test or Mann-Whitney U test, and the categorical data were compared by χ² test or Fisher exact probability method. The influencing factors of postoperative pancreatic fistula were analyzed by univariate and multivariate Logistic regression. Results: All patients successfully completed tumor enucleation without conversion to laparotomy. The operation time was (183.5±67.3)minutes(range:90 to 410 minutes). Twelve patients(20.0%) underwent stent placement and pancreatic duct repair during operation. The removal time of abdominal drainage tube after operation was (24.7±22.9)days(range:2 to 113 days). The tumor diameter in the robotic group was larger than that in the laparoscopic group((3.5±0.9)cm vs. (2.9±0.7)cm,t=-2.825,P=0.006). The incidences of postoperative biochemical fistula and grade B pancreatic fistula were 20.0%,22.9% and 36.0%,51.4%,respectively(χ²=2.289,P=0.318). There were no grade C pancreatic fistula,lymphatic fistula,biliary fistula,delayed gastric emptying,secondary operation and perioperative death in both groups. Multivariate logistic regression analysis was performed on the occurrence of clinically related pancreatic fistula(above grade B). The results showed that the increase of body mass index(OR=1.285,95%CI:1.053 to 1.569,P=0.014),the larger diameter of the tumor(OR=3.703,95%CI:1.465 to 9.360,P=0.006) and intraoperative pancreatic duct repair(OR=7.889,95%CI:1.471 to 42.296,P=0.016) were independent risk factors,whereas robotic surgery(OR=0.168,95%CI:0.036 to 0.796,P=0.025) was a protective factor. No case of pancreatin dependent dyspepsia and new onset diabetes mellitus was observed. Conclusions: Minimally invasive tumor enucleation is feasible in the treatment of benign and low-grade pancreatic tumors. The incidence of pancreatic fistula is high in the short term after operation,but serious complications are rare. The robot assisted system can reduce the risk of postoperative pancreatic fistula and has more advantages in dealing with larger diameter tumors because of clearer surgical vision and more accurate operation.

[The diagnosis and treatment of G3 neuroendocrine tumors according to the new NCCN guideline]

Gastrointestinal pancreas (GEP) is the most common site of neuroendocrine neoplasms (NENs). In 2019, the World Health Organization (WHO) classification for GEP NET was updated to include a new category of well-differentiated high-grade (Ki 67>20%) GEP-NET G3, distinct from high-grade poorly differentiated neuroendocrine carcinoma (NEC). As a new category, NET G3 are considered a molecularly, radiologically, and prognostically distinct entity compared to NEC and NET G1/G2. The management of NET G3 remains a challenge awaiting future trials taking into consideration the unique characteristics of this new category. The latest NCCN clinical guidelines of neuroendocrine and adrenal tumors firstly gave the recommendation of diagnosis and treatment of G3 NET separately from NEC and G1/G2 NET. Hereon,we aim to summarize the management of G3 NET in combination with the new NCCN guidelines and the current evidences.

[Efficacy of conversion therapy and direct surgical resection in patients with metastatic pancreatic neuroendocrine tumors]

Objective: To explore the prognosis of Chinese patients with metastatic pancreatic neuroendocrine tumor (PanNET) treated with conversion therapy and surgical resection. Methods: The pathological data and prognostic information was retrospectively collected of patients with metastatic PanNET treated in Fudan University Shanghai cancer center from January 2010 to May 2021, and propensity score matching was used to analyze the prognosis difference between conversion treatment followed surgery and direct surgery. Results: There were 58 males and 43 females in 101 patients with metastatic PanNET. The age raged from 18 to 74 years, with a median age of 51 years. A total of 88 patients received primary tumor with liver metastases resection, 1 receied of primary tumor resection and 12 received primary tumor resection and combined organs or extrahepatic metastases. Multivariate analysis showed that R2(HR=1.943,95%CI:1.262-2.990,P=0.003)resection and G3(HR=1.876,95%CI:1.001-3.516,P=0.05) were independent risk factors for postoperative progression of metastatic patients. There were 63 patients (62.4%) who had received direct surgery, and 38 patients (37.6%) who had received preoperative conversion therapy. The conversion therapy had a higher proportion of T3/T4 stage (68.1% vs 39.7%, P=0.007), resection with combined organs/extrahepatic metastasis (26.3% vs 9.5%, P=0.005) and R2 resection (71.1% vs 42.9%, P=0.005). The median progression-free survival (mPFS) between conversion therapy and direct surgery had no statistically significant, but after the propensity score matching the mPFS of the conversion therapy group was significantly longer than direct surgery group (HR=0.442,95%CI:0.207-0.943,P=0.027). Conclusions: Conversion therapy for partially metastatic PanNET is better than that of direct surgery. Radical resection and grade are independent prognostic factors for metastatic PanNET after resection.

[Effect of laparoscopic surgery for pancreatic cancer after neoadjuvant chemotherapy]

Objective: To evaluate the safety and feasibility of laparoscopic surgery after neoadjuvant chemotherapy for pancreatic cancer. Methods: Clinical data of 8 patients underwent laparoscopic surgery after neoadjuvant chemotherapy for pancreatic cancer at Fudan University Shanghai Cancer Center from September 2019 to June 2020 were reviewed retrospectively. There were 5 males and 3 females,aged from 47 to 72 years old. All patients underwent abdominal enhanced CT and PET-CT before operation to accurately evaluate the tumor stage and exclude distant metastasis. Results: Neoadjuvant chemotherapy with AG regimen(gemcitabine 1 000 mg/m² and albumin bound paclitaxel 125 mg/m²) was received for 2 to 6 cycles before surgery. All 8 patients successfully completed the operation,including 5 cases of pancreaticoduodenectomy,2 cases of radical antegrade modular pancreatosplenectomy(RAMPS),and 1 case of total pancreatectomy. No conversion to laparotomy or laparoscopic assisted surgery. The operation time was 240 to 450 minutes,the blood loss was 100 to 500 ml,the postoperative length of stay was 10 to 16 days. During the follow-up period up to December 31, 2020, there was 1 case suffered grade B pancreatic leakage and abdominal infection. The numbers of resected lymph nodes were 9 to 31. All patients received R0 resection. The follow-up times were 4.5 to 9.5 months. One patient underwent RAMPS was diagnosed as liver metastasis after 2 months of the operation,and the other 7 patients still survived without tumor recurrence. Conclusion: Minimally invasive surgery of pancreatic cancer after neoadjuvant chemotherapy is safe and feasible in experienced pancreatic minimally invasive centers.

[Establishment and validation of prediction model of new-onset pelvic organ prolapse in early postpartum period]

Objective: To analyze the risk factors of pelvic organ prolapse (POP) and to establish the prediction model. Methods: A study was conducted on the prevalence of POP among 2 247 parturient women at 6 weeks postpartum in Peking University People's Hospital from December 2018 to October 2019, and relevant influencing factors were analyzed to construct a prediction model of early postpartum POP using logsitic regression, which was validated internally. Data from November 2019 to December 2019 (403 parturient women) were collected for external validation of the prediction model. In addition, the obstetrical factors affecting the occurrence of early postpartum POP in 885 primiparas with vaginal delivery (from January 2019 to November 2019) were further discussed. Results: A total of 2 247 cases were included in the modeling group, and 403 cases were included in the external validation data set. POP accounted for 24.3% (545/2 247). Age, parity, body mass index before pregnancy, vaginal delivery and newborn birth weight were negative factors for early postpartum POP (all P<0.05). The nomogram was established based on the above factors, and internal and external verification indicated that the model had a good discrimination (C-index were 0.759 and 0.760, respectively). In addition, this study found that age and newborn birth weight were the main causes of early postpartum POP in primiparas with vaginal delivery (P=0.044, P=0.004). Conclusions: The incidence of early postpartum POP is high. The prediction model of POP constructed in this study could be used to guide clinical practice to a certain extent and give corresponding treatment suggestions to pregnant women scientifically, so as to provide theoretical support for primary prevention.

[Advances in basic and translational research in neuroendocrine neoplasms]

With the development of diagnostic techniques and the improvement of people's living standards, the detection rate of neuroendocrine tumor has been increasing and people are paying more and more attention to it. With multiple treatment modalities, the clinical research progress of neuroendocrine tumor is remarkable. However, due to the tumor heterogeneity, metastasis and recurrence of neuroendocrine tumor remains a difficult problem for clinicians. The efficacy of neuroendocrine tumor still needs to be improved. Therefore, the biological behavior of neuroendocrine tumor needs to be further studied. In recent years, with the development of molecular biology, the basic and transformation research of neuroendocrine tumor has made some progress. In this paper, we focus on the hot topics of neuroendocrine tumor, such as multiomics (copy number variation, genomics, transcriptomics), tumor microenvironment (immune microenvironment, tumor microvasculature, tumor-associated fibroblasts, etc.), preclinical research model construction (cell lines, organoids, patient derived xenograft models, genetically engineered mice), etc. Specifically, the related clinical transformation significance will be elaborated.

[Surgical treatment for pancreatic cancer with liver metastasis:exploration and innovation]

The prognosis of pancreatic cancer patients with liver metastasis (PCLM) is very poor and the median overall survival(OS) is less than 6 months.The current standard treatment for PCLM is systematic chemotherapy.Though the chemotherapeutic regimens are better than gemcitabine only,the OS remains dissatisfied.A lot of retrospective studies identified that surgical treatment can only offer survival benefits for highly selected rather than entire PCLM patients.The Chinese Study Group for Pancreatic Cancer (CSPAC) has initiated a multiple-center,prospective,randomized comparison clinical trial,named CSPAC-1 to identify the standard and value of surgical treatment of PCLM patients.This manuscript reviewed the current progress of surgical treatment for pancreatic cancer with liver metastasis and looked forward to opportunities and challenges in the future.

Essential roles of plexin-B3+ oligodendrocyte precursor cells in the pathogenesis of Alzheimer's disease

The role of oligodendrocyte lineage cells, the largest glial population in the adult central nervous system (CNS), in the pathogenesis of Alzheimer's disease (AD) remains elusive. Here, we developed a culture method for adult oligodendrocyte progenitor cells (aOPCs). Fibroblast growth factor 2 (FGF2) promotes survival and proliferation of NG2+ aOPCs in a serum-free defined medium; a subpopulation (~5%) of plexin-B3+ aOPCs was also found. FGF2 withdrawal decreased NG2+, but increased plexin-B3+ aOPCs and Aβ1-42 secretion. Plexin-B3+ aOPCs were distributed throughout the adult rat brain, although less densely than NG2+ aOPCs. Spreading depolarization induced delayed cortical plexin-B3+ aOPC gliosis in the ipsilateral remote cortex. Furthermore, extracellular Aβ1-42 accumulation was occasionally found around plexin-B3+ aOPCs near the lesions. In AD brains, virtually all cortical SPs were immunostained for plexin-B3, and plexin-B3 levels increased significantly in the Sarkosyl-soluble fractions. These findings suggest that plexin-B3+ aOPCs may play essential roles in AD pathogenesis, as natural Aβ-secreting cells.

[The Chinese guidelines for the diagnosis and treatment of pancreatic neuroendocrine neoplasms (2020)]

Pancreatic neuroendocrine neoplasms (pNENs) are highly heterogeneous, and the management of pNENs patients can be intractable. To address this challenge, an expert committee was established on behalf of the Group of Pancreatic Surgery, Chinese Society of Surgery, Chinese Medical Association, which consisted of surgical oncologists, gastroenterologists, medical oncologists, endocrinologists, radiologists, pathologists, and nuclear medicine specialists. By reviewing the important issues regarding the diagnosis and treatment of pNENs, the committee concluded evidence-based statements and recommendations in this article, in order to further improve the management of pNENs patients in China.

[Analysis of magnetic resonance imaging findings of fungal spondylitis]

The clinical and magnetic resonance imaging(MRI) data of 8 cases of fungal spondylitis were retrospectively enrolled in the study, and the typical MRI findings were mainly discussed. The results released that fungal spondylitis should be suspected when the infection spreads along paraspinal ligament, and vertebral lesions show jumping discontinuous distribution. A blurred and incomplete outline of endplate on T1 weighted imaging sequence, loss of hyperintensity of the vertebral body, and banded like hypointensity under endplate on T₂ weighted imaging sequence, indicate fungal spondylitis. These features contribute to the diagnosis and differential diagnosis of fungal spondylitis.

Structure of the cytoplasmic domain of SctV (SsaV) from the Salmonella SPI-2 injectisome and implications for a pH sensing mechanism

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CryoEM of a full-length type III secretion system SctV resolves cytoplasmic but not transmembrane domains.

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MD simulations show SctV protomers flexibly hinge.

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Acidification expands the SctV ring by altering interprotomer interactions.

Bacterial type III secretion systems assemble the axial structures of both injectisomes and flagella. Injectisome type III secretion systems subsequently secrete effector proteins through their hollow needle into a host, requiring co-ordination. In the Salmonella enterica serovar Typhimurium SPI-2 injectisome, this switch is triggered by sensing the neutral pH of the host cytoplasm. Central to specificity switching is a nonameric SctV protein with an N-terminal transmembrane domain and a toroidal C-terminal cytoplasmic domain. A ‘gatekeeper’ complex interacts with the SctV cytoplasmic domain in a pH dependent manner, facilitating translocon secretion while repressing effector secretion through a poorly understood mechanism. To better understand the role of SctV in SPI-2 translocon-effector specificity switching, we purified full-length SctV and determined its toroidal cytoplasmic region’s structure using cryo-EM. Structural comparisons and molecular dynamics simulations revealed that the cytoplasmic torus is stabilized by its core subdomain 3, about which subdomains 2 and 4 hinge, varying the flexible outside cleft implicated in gatekeeper and substrate binding. In light of patterns of surface conservation, deprotonation, and structural motion, the location of previously identified critical residues suggest that gatekeeper binds a cleft buried between neighboring subdomain 4s. Simulations suggest that a local pH change from 5 to 7.2 stabilizes the subdomain 3 hinge and narrows the central aperture of the nonameric torus. Our results are consistent with a model of local pH sensing at SctV, where pH-dependent dynamics of SctV cytoplasmic domain affect binding of gatekeeper complex.

[Impact of neoadjuvant therapy on the perioperative complications of pancreatic cancer]

Pancreatic cancer is one of the most malignant digestive tract tumors with a 5-year survival rate of less than 10%. Surgery remains the basis of long-term survival of pancreatic cancer patients. With the progress of chemotherapy, neoadjuvant therapy has been gradually carried out in pancreatic cancer. There are more and more studies on the effects of neoadjuvant therapy on perioperative complications of pancreatic cancer, but the results are not consistent. This article reviews the recent studies on neoadjuvant therapy for pancreatic cancer and analyzes the impact of some key factors on perioperative complications.

Synthesis of TEMPO radical decorated hollow porous aromatic frameworks for selective oxidation of alcohols

A bottom-up approach was developed to prepare TEMPO radical decorated hollow aromatic frameworks (HPAF-TEMPO) by using TEMPO radical functionalized monomers and SiO2 nanospheres as templates. The accessible inner layer, high density of TEMPO sites, and hybrid micro-/mesopores of the HPAF-TEMPO enable the aerobic oxidation of a broad range of alcohols with high efficiency and excellent selectivity.

[COVID-19 epidemic and its characteristics in Heilongjiang province]

Objective: To describe the COVID-19 epidemic and its characteristics in Heilongjiang province, and provide evidence for the further prevention and control of COVID-19 in the province. Methods: The information of COVID-19 cases and clusters were collected from national notifiable disease report system and management information system for reporting public health emergencies of China CDC. The Software's of Excel 2010 and SPSS 23.0 were applied for data cleaning and statistical analysis on the population, time and area distributions of COVID-19 cases. Results: On January 22, 2020, the first confirmed case of COVID-19 was reported in Heilongjiang. By March 11, 2020, a total of 482 cases domestic case of COVID-19, The incidence rate was 1.28/100 000, the mortality rate was 2.70% (13/482) in 13 municipalities in Heilongjiang. There were 81 clusters of COVID-19, The number of confirmed cases accounted for 79.25% (382/482) of the total confirmed cases and 12 cases of deaths. The family clusters accounted for 86.42% (70/81). Compared with the sporadic cases, the mortality rate, proportion of elderly cases aged 60 or above and severe or critical cases of clinical classification were all higher in the clusters especially the family clusters, but the differences were not significant (P>0.05). There were 34 clusters involving more than 5 confirmed cases accounted for 41.98% (34/81) of the total clusters, the involved cases accounted for 68.31% (261/382) of the total cases of clusters. There were significant differences in age distribution of the cases among the case clusters with different case numbers. In the clusters involving 6-9 cases, the proportion of cases aged 65 years or above was more (26.53%, 39/147). Conclusions: The incidence rate of COVID-19 was relatively high and the early epidemic was serious in Heilongjiang, The number of cases was large in clusters especially family clusters.

Highly oriented and polyoxometalate-incorporating surface-attached metal-organic frameworks for efficient dye adsorption and water oxidation

We present a facile protocol for the controlled growth of highly oriented and polyoxometalate-incorporating HKUST-1 SURMOFs. Combining the spin-coating technique with alcohol-vapour induced growth, film thickness, crystallite orientation and crystal size can be precisely tuned. The SURMOFs exhibit excellent abilities in selective adsorption of cationic dyes and water oxidation.

Skimmed Milk Diluent Promotes the Sperm Motility and Conception Rate of Dorper Sheep Compared to Vitamin B12 Diluent

BACKGROUND

Dorper sheep is an ideal breed for improvement, with higher meat production and increased adaptability. Artificial insemination is an efficient technique for Dorper genetic improvement and reproduction management. However, there is no uniform diluent for Dorper semen dilution.

OBJECTIVE

To compare the effects of vitamin B12 (VB12) and skimmed milk diluents on sperm motility at different ratios and time points, and the effects on conception rate.

MATERIALS AND METHODS

We detected the effect of diluents on sperm density, deformity, motility and conception rate of Dorper sheep.

RESULTS

We found the optimal dilution ratio of skimmed milk is 1:3. Compared to VB12, skimmed milk at 1:3 ratio prolonged semen storage time (48 h vs. 18 h, storage at a low temperature of 4°C) and increased the survival index of sperm (44.7 ± 2.8 vs. 18.5 ± 0.6, P<0.01).

CONCLUSION

Skimmed milk is more effective, nutritious and convenient than vitamin B12, representing a more advantageous diluent.

Concentration-Dependent Seeding as a Strategy for Fabrication of Densely Packed Surface-Mounted Metal-Organic Frameworks (SURMOF) Layers

The layer‐by‐layer (LbL) method is a well‐established method for the growth of surface‐attached metal–organic frameworks (SURMOFs). Various experimental parameters, such as surface functionalization or temperature, have been identified as essential in the past. In this study, inspired by these recent insights regarding the LbL SURMOF growth mechanism, the impact of reactant solutions concentration on LbL growth of the Cu₂(F₄bdc)₂(dabco) SURMOF (F₄bdc²⁻=tetrafluorobenzene‐1,4‐dicarboxylate and dabco=1,4‐diazabicyclo‐[2.2.2]octane) in situ by using quartz‐crystal microbalance and ex situ with a combination of spectroscopic, diffraction and microscopy techniques was investigated. It was found that number, size, and morphology of MOF crystallites are strongly influenced by the reagent concentration. By adjusting the interplay of nucleation and growth, we were able to produce densely packed, yet thin films, which are highly desired for a variety of SURMOF applications.

[Pelvic floor function of 5 143 women in early postpartum stage and analysis on the effect factors]

Objective: To describe the situation of early stage of pelvic floor function and investigate the effect factors in postpartum women. Methods: A retrospective survey was conducted, and women who did regular examination and gave birth in Peking University People's Hospital and had an annual pelvic floor examination at 6-12 weeks after delivery from Sep. 2012 to Dec. 2017 were interviewed. General information and pelvic floor electrical physiological indexes were collected and analyzed. Results: Totally 5 143 puerpera were included in the study. The normal strength of type Ⅰ muscle was 52.40% (2 695/5 143) and the normal strength of type Ⅱ muscle was 52.69% (2 710/5 143). The abnormal degree of fatigue of type Ⅰ muscle was 55.84% (2 872/5 143) and the abnormal degree of fatigue of typeⅡmuscle was 27.34% (1 406/5 143). Pelvic floor dynamic pressure was (93±37) cmH(2)O (1 cmH(2)O=0.098 kPa). The incidence of stress urinary incontinence (SUI) was 23.49% (1 208/5 143) after delivery and it was as high as 57.58% (95/165) for women who had family history of pelvic floor dysfunction. Family history of pelvic floor dysfunction was the risk factor of the fatigue index of type Ⅰ and type Ⅱ muscle (P<0.05). The incidence of SUI was associated with vaginal delivery and age (≥30 years old) and family history of pelvic floor dysfunction (P<0.01). Conclusions: Pelvic floor electrical physiological indicators are reduced in about half of women in early postpartum stage. Age (≥30 years old) and vaginal delivery and family history of pelvic floor dysfunction are the risk factors.

[A prospective cohort study on the duration of sleep and risk of all-cause mortality among patients with type 2 diabetes]

Objective: To investigate the relationship between duration of sleep and all-cause mortality in patients with type 2 diabetes. Methods: A total of 17 452 type 2 diabetic patients who were under the National Basic Public Health Service Project, in Changshu county, Qinghe district and Huai'an district in Huai'an city of Jiangsu province, were recruited as participants. Cox proportional hazards regression models were used to estimate the associations between different levels on the duration of sleep and all-cause mortality. Stratified analysis was performed according to factors as gender, age, and lifestyle. Results: Among the 67 912 person-years of observation, from the fo1low- up program, the median time of follow-up was 4 years, with 1 057 deaths occurred during the follow-up period. Taking patients with duration of sleep as 7 h/d for reference, the multivariate adjusted hazard ratios (95%CI) of all-cause mortality appeared as ≤6, 8, 9 and ≥10 h/d were 1.14 (0.94-1.37), 1.10 (0.91-1.32), 1.33 (1.05-1.70), and 1.52 (1.24-1.87), respectively which were associated with the duration of sleep. Data from the subgroup analysis showed that this was consistent with the whole population. Longer duration of sleep was associated with the all-cause mortality but no significant association was found between shorter duration of sleep and the all-cause mortality. Conclusion: Longer duration of sleep seemed to have increased the risk of all-cause mortality in type 2 diabetic patients.

Liver Tissue-related Metabolic Mechanism of Different Infusion Volumes for Hemorrhagic Shock

OBJECTIVES

To investigate the curative effects of various infusion volumes on liver-related metabolic mechanism in the treatment of hemorrhagic shock.

METHODS

A severe hemorrhagic shock rabbit model was established in 30 rabbits. The rabbits were randomly divided into three groups： non-infusion group （A）, conventional infusion group （B）, and excessive infusion group （C） （n=10 in each group）. Taking group B as the control, groups A and C were observed for the damage of non-infusion and excessive infusion, respectively. The outcomes in the three groups and their relations with liver tissue metabolism changes were analyzed with gas chromatograph-mass spectrometer （GC-MS）.

RESULTS

The mortality in groups A, B, and C group were 80%, 0%, and 70%, respectively. The liver tissue metabolic profile in group B showed statistically significant difference compared with that in groups A and B. In group C, the levels of 21 metabolites were lower than those in group B, and the levels of 8 metabolites were lower than those in group A. The relative contents of various metabolites were correlated with infusion volumes, and the succinic acid content was associated with death events （P<0.05）.

CONCLUSIONS

The conventional infusion has significant curative effect on hemorrhagic shock. The metabolites of liver tissues with excessive infusion are generally decompensated and have longer survival time than those in non-infusion group, which may caused by the excessive infusion-induced blood volume increase after hemorrhagic shock. Tissue fluid dilution is an important cause of death.

[Contamination and pathogenicity analysis of listeria monocytogenes in restaurant in Heilongjiang Province]

Objective: To study the contamination, serotype, pulsed field gel electrophoresis (PFGE) and drug resistance of listeria monocytogenes (L.monocytogenes) in the process of restaurant kitchens in Heilongjiang Province. Methods: Seventeen typical restaurants were selected from three cities in Heilongjiang Province in 2016, and 590 kitchen samples were collected and tested according to the national standard method. The serotype, pulsed field gel electrophoresis (PFGE) and drug resistance of isolated strains were analyzed. Results: L. monocytogenes was found in 104 of 590 of the samples analysed (17.63%). The isolates belong to six serotypes (1/2 a, 1/2 b, 1/2c, 3a, 3 b, 4 b) and self-condensing bacteria, and 57.38% (70 strains) of the strains belong to serotype 1/2b. Two highly pathogenic serotype 4b was detected for human listeria disease. The results of PFGE analysis show that the bacteria have cross-contamination in the environment, tools, equipment, food and personnel. The drug resistance results showed that 2 strains were resistant to tetracycline, 1 strain was resistant to erythromycin, 13 strains were intermediate to tetracycline, and 2 strains were resistant to tetracycline and erythromycin. Conclusion: There is a certain degree of L. monocytogenes cross-contamination in the catering kitchen in Heilongjiang Province. And an important serotype 4b that can cause human Listeria disease was detected.

[The expression and clinical significance of proprotein convertase subtilisin kexin 9 in rheumatoid arthritis]

Objective: To assess the expression and significance of proprotein convertase subtilisin kexin 9 (PCSK9) in patients with rheumatoid arthritis (RA). Methods: Sixty-five RA patients and forty-seven healthy controls were recruited in this study. The body mass index (BMI) and serum total cholesterol(TC), triglyceride(TG), high density lipoprotein(HDL), lipoprotein a, low density lipoprotein(LDL), very low density lipoprotein(VLDL), apolipoprotein A(ApoA), apolipoprotein B(ApoB) and the ratio of LDL-C/HDL-C were tested. Other parameters included disease activity score 28(DAS28), rheumatoid factor (RF), anti-cyclic citrullinated peptide (CCP) antibody, erythrocyte sedimentation rate (ESR), c-reactive protein (CRP). Serum PCSK9 level was measured by ELISA and compared between RA patients and healthy controls. Results: (1) The serum PCSK9 levels in RA patients were higher than those in healthy controls[(409.36±223.52) μg/L vs (292.19±109.79) μg/L, P<0.05]. (2) Compared with subgroup of moderate and low active disease and patients in remission, PCSK9 was significantly higher in patients with highly active disease (P<0.05). (3) The serum PCSK9 levels were positively correlated with RF, TC, TG, LDL, very low density lipoprotein (VLDL), ApoB, with r values as 0.303, 0.490, 0.320, 0.451, 0.319, 0.463, respectively (P<0.05). (4) Multiple stepwise regression analysis showed that DAS28, RF, TC and LDL-C/HDL-C were relevant factors for PCSK9 in RA patients. Conclusions: The serum PCSK9 level is elevated in RA patients, which is related to RF, disease activity, TC, TG, LDL, VLDL, ApoB. This suggests that PCSK9 is potentially linked to inflammatory reaction and lipid metabolism in rheumatoid arthritis.

A soft x-ray-ultraviolet (SUV) beamline and diffractometer for resonant elastic scattering and ultraviolet-vacuum ultraviolet reflectance at the Singapore synchrotron light source

A new beamline and a six-circle UHV diffractometer have been constructed at the Singapore Synchrotron Light Source with a broad energy coverage from 3.5 to 1500 eV. The beamline is optimized for ultraviolet-vacuum-ultraviolet optical reflectivity and resonant soft X-ray scattering with medium energy resolution over a broad energy range, achieved by using a self-focusing monochromator consisting of a plane mirror and three variable line spacing gratings. The unique character of the diffractometer comprises 4-circles in the vertical plane and 2-circles in the horizontal plane. Thirteen motions are available inside the UHV chamber with a base pressure of 1 × 10^-9 mbar. Two sample holders working independently over a temperature range of 37 K-400 K are controlled by a closed-cycle cryostat, while the bottom holder inside a high field compact pulsed magnet is available for measurements requiring a magnetic field.

[2017 ENETS consensus guidelines: update for the standard of care of pancreatic neuroendocrine tumors]

Neuroendocrine tumors(NET) is a rare tumor with high heterogeneity.Pancreatic NET is the most common type in China. European Neuroendocrine Tumor Society(ENETS) has launched the ENETS guidelines since 2006 and published the ENETS standard of care in 2009. With the newly targeted therapies and further research on NET, 2017 new edition of the ENETS standard of care has changed a lot in the diagnosis and treatment of NET. This article explains the update of pancreatic NET in the 2017 edition of the ENETS standard of care, and introduces pancreatic NET from pathology, imaging examination, surgery, systemic therapy, etc., and deepens the understanding of the diagnosis and treatment of pancreatic NET.

[Construction of cochlear progenitor cells with recombinant short-hairpin RNA lentiviral vector inhibiting the expression of the β-catenin gene]

Objective: To construct a recombinant short-hairpin RNA (shRNA) lentiviral vector targeting the β-catenin gene in cochlear precursor cells (CPCs) in mice, and to investigate its inhibitory effect. Methods: PCR was used for the multiplication of the β-catenin gene, and shRNA oligo was designed based on the β-catenin gene to construct an interference vector. Gateway Technology was used to construct shRNA lentiviral vector which carried the β-catenin gene, and then 293FT cells were transfected with the constructed lentiviral vector and helper plasmids pLV/helper-SL3, pLV/helper-SL4, and pLV/helper-SL5. The virus supernatant was collected to obtain viral particles, and then mouse CPCs were transiently infected with the recombinant lentivirus with four different concentrations (0, 5, 10, and 20 μl) . The shRNA control group was established. Quantitative real-time PCR and Western blot were used to investigate the inhibitory effect of shRNA β-catenin lentiviral vector on β-catenin. Results: The recombinant shRNA β-catenin lentiviral vector was successfully constructed, and the virus titers of shβ-catenin and shβ-catenin-control were 5.05×10(7) and 4.34×10(7), respectively. The results of in vitro experiments showed that in CPCs transfected with four different concentrations of recombinant lentivirus, the content of β-catenin protein gradually decreased with the increase in concentration, and there was a significant difference between groups (P<0.05) ; the CPCs transfected with shβ-catenin had significantly lower mRNA expression of β-catenin than those in the shβ-catenin-control group (P<0.05) . Conclusion: The constructed lentiviral vector targeting the β-catenin gene has a high infection efficiency, and the successful construction of lentiviral vectors provides a technical support for analyzing the role of β-catenin in the differentiation of CPCs into auditory hair cells.

[Reconstruction of nasal defects of multiple subunits with lateral nasal artery pedicled nasolabial flap]

Objective:To evaluate the effectiveness of the lateral nasal artery pedicled nasolabial flap for reconstruction of nasal defects of multiple subunits. Method:From September 2014 to April 2016, 30 cases of nasal defects in multiple subunits repaired with the lateral nasal artery pedicled nasolabial flap were retrospectively analysed. Result:All flaps survived. Incision at donor and accepted sites healed by first intention. Two patients had mild venous stasis 24 hours after operation and can alleviated spontaneously. Flap revision was performed in 25 cases after 3-6 months. Twentythree cases were followed up 3-12 months. All patients achieved satisfactory results in nasal appearance. Conclusion:The lateral nasal artery pedicled nasolabial flap can reconstruct the nasal defects of multiple subunits, and the texture, color or thickness are similar to the surrounding skin.It is one of the effective methods to repair multiple subunits of nasal defects.

[Metabolic Characteristics of Lethal Bradycardia Induced by Myocardial Ischemia]

OBJECTIVES

To explore the metabolic characteristics of lethal bradycardia induced by myocardial ischemia in rat's serum.

METHODS

A rat myocardial ischemia-bradycardia-sudden cardiac death （MI-B-SCD） model was established, which was compared with the sham-operation group. The metabolic profile of postmortem serum was analyzed by gas chromatography-mass spectrometry （GC-MS）, coupled with the analysis of serum metabolic characteristics using metabolomics strategies.

RESULTS

The serum metabolic profiles were significantly different between the MI-B-SCD rats and the control rats. Compared to the control rats, the MI-B-SCD rats had significantly higher levels of lysine, ornithine, purine, serine, alanine, urea and lactic acid; and significantly lower levels of succinate, hexadecanoic acid, 2-ketoadipic acid, glyceraldehyde, hexendioic acid and octanedioic acid in the serum. There were some correlations among different metabolites.

CONCLUSIONS

There is obvious metabolic alterations in the serum of MI-B-SCD rat. Both lysine and purine have a high value in diagnosing MI-B-SCD. The results are expected to provide references for forensic and clinical applications of prevention and control of sudden cardiac death.

Facet orientation and tropism: Associations with asymmetric lumbar paraspinal and psoas muscle parameters in patients with chronic low back pain

BACKGROUND

Many studies have explored the relationship between facet tropism and facet joint osteoarthritis, disc degeneration and degenerative spondylolisthesis. However, the associations between facet orientation and tropism, and paraspinal muscles have not been studied.

OBJECTIVE

To analyze the associations between facet orientation and tropism, and parameters of paraspinal muscles in patients with chronic low back pain.

METHODS

Ninety-five patients with chronic low back pain were consecutively enrolled. Their facet joint angles were measured on computed tomography (CT) while gross cross-sectional area (GCSA), functional cross-sectional area (FCSA) and T2 signal intensity of lumbar paraspinal and psoas muscle were evaluated on magnetic resonance imaging (MRI).

RESULTS

The GCSA and FCSA were significantly smaller for multifidus muscle (P< 0.001), but significantly larger for erector spinae and psoas muscles (P< 0.001), in coronally-orientated group than those in sagittally-orientated group. The differences of bilateral GCSA and FCSA of multifidus muscle were significantly larger in facet tropism group than those in no facet tropism group (P= 0.009 and P= 0.019).

CONCLUSIONS

Muscular asymmetries may develop in the lumbar region of the spine, which are associated with facet asymmetry in patients with chronic low back pain. Longitudinal studies are needed to understand the causal relationship between facet orientation and tropism and muscular asymmetry in future.

[The corneal biomechanical properties of patients with Graves' orbitopathy]

OBJECTIVE

This study aims to compare the corneal biomechanical properties of patients with Graves'orbitopathy (GO) with normal people and analysis the correlated factors.

METHODS

Retrospective case series study. 34 eyes of 20 patients (6 eyes are unilateral) diagnosed with inactive Graves' orbitopathy and 25 eyes of 14 patients (3 eyes are unilateral) diagnosed with active Graves' orbitopathy were recruited as study group. 30 eyes of 28 healthy volunteers with age and sex-matched were enrolled as control group in the affiliated eye hospital of Wenzhou medical university from December 2013 to June 2014. Central corneal thickness (CCT) measured with A ultrasound, corneal hysteresis (CH) measured with Ocular Response Analyser (ORA), corneal resistance factor (CRF), Goldman-corrected IOP value (IOPg) and Cornea-Compensated Intraocular Pressure(IOPcc) were collected. An ANONA and Kruskal-Wallis Test was used to compare the indexes mentioned above.

RESULTS

The mean age of inactive group was (47.3±12.8)y (23 eyes were female, 11 eyes were male), the mean age of active group was (51.9±9.6)y (16 eyes were female, 9 eyes were male) , the mean age of normal group was (47.2±10.4)y (19 eyes were female, 9 eyes were male). CH of inactive group was (9.68±1.45) mmHg, (1 mmHg=0.133 kPa), CH of active group was (9.82±1.53) mmHg, lower than the CH of (10.67±1.68) mmHg in control group, which was statistically significant different (t1=-2.51,P1=0.014,t2=-2.01,P2=0.048). IOPcc of inactive group was (17.91±3.67) mmHg, IOPcc of active group was (17.88±5.44) mmHg, which were higher than the IOPcc of (13.90±3.39) mmHg in the control group, which was statistically significant different (t1=3.76,P1=0.001;t2= 3.461,P2=0.001). There were no significant difference between study and control group in CRF, that was in inactive group (10.19±1.73)mmHg, active group (10.36±1.01)mmHg, normal group (10.08±1.40)mmHg respectively (t1=0.31,P=0.761;t2=0.69,P2=0.491). CCT of inactive group was (531.41±37.60) μm, CCT of active group is (533.52±18.88) μm, which had no statistical significant difference from the CCT of (546.25±28.84) μm in control group (t1=-1.91,P=0.059;t2=-1.52,P2=0.132). Corneal hysteresis was negatively correlated with exophthalmos, IOPg, IOPcc (Pearson=-0.279,-0.385,-0.663,P<0.05), and positively correlated with corneal central thickness and corneal resistance factor (Pearson=0.246,0.583,P<0.05) in TAO group.

CONCLUSIONS

Cornea hysteresis of TAO patients decreased, combined with lower ability of cornea to recover to the primary conditions when upon pressure. CH was negatively correlated with IOPg and IOPcc.(Chin J Ophthalmol, 2016, 52: 263-267).

Alpaca fiber growth is mediated by microRNA let-7b via down-regulation of target gene FGF5

MicroRNAs are very small endogenous RNA molecules that play a crucial role in an array of biological processes, including regulation of skin morphogenesis. The microRNA let-7b is thought to modulate animal hair growth, by binding target genes that encode growth factors. Fibroblast growth factor 5 (FGF5) has been previously reported to be involved in the initiation of the catagen phase of hair growth. In this study, we combined previous reports with bioinformatic analysis techniques to identify and validate FGF5 and, using lucerifase assay, confirmed targeted binding of let-7b to FGF5. To investigate the interaction between let-7b and FGF5, alpaca skin fibroblasts were transfected with let-7b over-expression vectors, and then mRNA and protein expression levels of FGF5 and the gene encoding its receptor, FGFR1, were evaluated. Levels of FGF5 mRNA and protein were remarkably lower in transfected groups, as compared to controls. In summary, this study confirmed that let-7b acts as a regulator of skin morphogenesis, by directly targeting FGF5 and down-regulating its expression. It provides the evidence of hair growth regulated by miRNAs in animals and may have important applications in wool production.

Depression and Alzheimer's disease: novel postmortem brain studies reveal a possible common mechanism

The relationship between depression and Alzheimer's disease (AD) has always been relevant and controversial. Here, we briefly review epidemiological and biological studies that have investigated these disorders and then introduce our recent research about postmortem brains from patients with major depressive disorder (MDD). Our novel methodological approaches have revealed that MDD may be associated with an unknown type of myelin/myelination abnormalities in the frontopolar cortex. Based mainly on our findings, as well as on neuropathological observations by Braak and Braak (Acta Neuropathol 9, 197-201, 1996), we discuss the possible existence of an as yet unknown common mechanism linking the pathophysiologies underlying both depression and AD.

Patterned deposition of metal-organic frameworks onto plastic, paper, and textile substrates by inkjet printing of a precursor solution

Flexible in many aspects: inkjet printing of metal-organic frameworks permits their larger area, high-resolution deposition in any desired pattern, even in the form of gradients or shades. When flexible substrates are used, many applications can be envisioned, such as sensing and capture of hazardous gases for personal safety measures.

Tandem translation generates a chaperone for the Salmonella type III secretion system protein SsaQ

Type III secretion systems (T3SSs) of bacterial pathogens involve the assembly of a surface-localized needle complex, through which translocon proteins are secreted to form a pore in the eukaryotic cell membrane. This enables the transfer of effector proteins from the bacterial cytoplasm to the host cell. A structure known as the C-ring is thought to have a crucial role in secretion by acting as a cytoplasmic sorting platform at the base of the T3SS. Here, we studied SsaQ, an FliN-like putative C-ring protein of the Salmonella pathogenicity island 2 (SPI-2)-encoded T3SS. ssaQ produces two proteins by tandem translation: a long form (SsaQ(L)) composed of 322 amino acids and a shorter protein (SsaQ(S)) comprising the C-terminal 106 residues of SsaQ(L). SsaQ(L) is essential for SPI-2 T3SS function. Loss of SsaQ(S) impairs the function of the T3SS both ex vivo and in vivo. SsaQ(S) binds to its corresponding region within SsaQ(L) and stabilizes the larger protein. Therefore, SsaQ(L) function is optimized by a novel chaperone-like protein, produced by tandem translation from its own mRNA species.

Investigation of Cu(II) adsorption from aqueous solutions by NKF-6 zeolite

Adsorption of Cu(II) from aqueous solutions using NKF-6 zeolite was investigated by batch technique under ambient conditions. The adsorption was investigated as a function of pH, ionic strength, fulvic acid (FA), foreign ions and temperature. The results indicated that the adsorption of Cu(II) on NKF-6 zeolite gradually increases from 0 to 90% with increasing pH at pH<6.5, and maintains high level at pH>6.5. Outer-sphere complexation or ion exchange may be the main adsorption mechanism of Cu(II) to NKF-6 zeolite at low pH values, whereas the adsorption of Cu(II) at pH>6.5 is mainly dominated by inner-sphere complexation or precipitation. A positive effect of FA on Cu(II) adsorption onto NKF-6 zeolite is observed at low pH values, while a negative effect of FA is observed at high pH values. The thermodynamic parameters (i.e., ΔH0, ΔS0 and ΔG0) for the adsorption of Cu(II) were determined from the temperature dependent isotherms at 20, 40 and 60°C, respectively, and the results indicated that the adsorption reaction is favoured at low temperature. The results suggested that the adsorption process of Cu(II) on NKF-6 zeolite is spontaneous and exothermic.

pH sensing by intracellular Salmonella induces effector translocation

Salmonella enterica is an important intracellular bacterial pathogen of humans and animals. It replicates within host-cell vacuoles by delivering virulence (effector) proteins through a vacuolar membrane pore made by the Salmonella pathogenicity island 2 (SPI-2) type III secretion system (T3SS). T3SS assembly follows vacuole acidification, but when bacteria are grown at low pH, effector secretion is negligible. We found that effector secretion was activated at low pH from mutant strains lacking a complex of SPI-2-encoded proteins SsaM, SpiC, and SsaL. Exposure of wild-type bacteria to pH 7.2 after growth at pH 5.0 caused dissociation and degradation of SsaM/SpiC/SsaL complexes and effector secretion. In infected cells, loss of the pH 7.2 signal through acidification of host-cell cytosol prevented complex degradation and effector translocation. Thus, intravacuolar Salmonella senses host cytosolic pH, resulting in the degradation of regulatory complex proteins and effector translocation.