Human amniotic epithelial cell transplantation for the repair of injured brachial plexus nerve: evaluation of nerve viscoelastic properties

The transplantation of embryonic stem cells can effectively improve the creeping strength of nerves near an injury site in animals. Amniotic epithelial cells have similar biological properties as em-bryonic stem cells; therefore, we hypothesized that transplantation of amniotic epithelial cells can repair peripheral nerve injury and recover the creeping strength of the brachial plexus nerve. In the present study, a brachial plexus injury model was established in rabbits using the C6root avulsion method. A suspension of human amniotic epithelial cells was repeatedly injected over an area 4.0 mm lateral to the cephal and caudal ends of the C6 brachial plexus injury site （1 × 106 cells/mL, 3μL/injection, 25 injections） immediately after the injury. The results showed that the decrease in stress and increase in strain at 7,200 seconds in the injured rabbit C6 brachial plexus nerve were mitigated by the cell transplantation, restoring the viscoelastic stress relaxation and creep properties of the brachial plexus nerve. The forepaw functions were also signiifcantly improved at 26 weeks after injury. These data indicate that transplantation of human amniotic epithelial cells can effec-tively restore the mechanical properties of the brachial plexus nerve after injury in rabbits and that viscoelasticity may be an important index for the evaluation of brachial plexus injury in animals.

Compensatory recombination phenomena of neurological functions in central dysphagia patients

We speculate that cortical reactions evoked by swallowing activity may be abnormal in patients with central infarction with dysphagia. The present study aimed to detect functional imaging features of cerebral cortex in central dysphagia patients by using blood oxygen level-depen- dent functional magnetic resonance imaging techniques. The results showed that when normal controls swallowed, primary motor cortex （BA4）, insula （BA13）, premotor cortex （BA6/8）, supramarginal gyrus （BA40）, and anterior cingulate cortex （BA24/32） were activated, and that the size of the activated areas were larger in the left hemisphere compared with the right. In re- current cerebral infarction patients with central dysphagia, BA4, BA13, BA40 aild BA6/8 areas were activated, while the degree of activation in BA24/32 was decreased. Additionally, more areas were activated, including posterior cingulate cortex （BA23/31）, visual association cortex （BA18/19）, primary auditory cortex （BA41） and parahippocampal cortex （BA36）. Somatosen- sory association cortex （BA7） and left cerebellum in patients with recurrent cerebral infarction with central dysphagia were also activated. Experimental findings suggest that the cerebral cortex has obvious hemisphere lateralization in response to swallowing, and patients with recurrent cerebral infarction with central dysphagia show compensatory recombination phenomena of neurological functions. In rehabilitative treatment, using the favorite food of patients can stimu- late swallowing through visual, auditory, and other nerve conduction pathways, thus promoting compensatory recombination of the central cortex functions.

混合气体气水分离过程中节流装置的建模方法及仿真分析（英文）

从天然气中分离水分是一个复杂过程,气体混合只有通过节流效应才能使其温度达到露点以分离水分和碳氢化合物,而节流装置参数识别和分析的准确性将直接影响分离效果,因此通过研究气流通过节流阀时保持气流畅通的流动条件,在临界状态下通过Saint-Venant-Wantzel方程在高压条件下建立了通过节流阀气体的流动模型。同时,基于通道中"节流阀横截面面积/流体温度的值"和"节流阀横截面面积/流速的值"的互连控制,研究了节流阀横截面积值对湿度LTS下节流量的速率和温度之间的非线性特性,明确该条件下气水分离的条件限制,最终建立了亚临界状态下节流装置静态模型。在ANSYS环境下对节流效应下的流体进行仿真实验,仿真结果表明:在节流阀的不同初始参数设定下,提出的模型均能对节流阀参数进行准确识别,并能在亚临界模式下对限制性条件做出正确的分析。

Inhibition of Girdin enhances chemosensitivity of colorectal cancer cells to oxaliplatin

AIM: To investigate the effect of Girdin knockdown on the chemosensitivity of colorectal cancer cells to oxaliplatin and the possible mechanisms involved.METHODS: Four siRNAs targeting Girdin were transfected into the chemoresistant colorectal cancer cell line DLD1. Real-time polymerase chain reaction(PCR) was employed to assess Girdin mRNA expression and the most effective siRNA was chosen for conversion into shRNA. Then, DLD1 cells were infected with lentiviruses expressing the Girdin shRNA and a scramble control, respectively, and Girdin mRNA and protein expression levels were assessed by real-time PCR and Western blotting. Furthermore, microarray experiments were used to assess global gene expression profile after Girdin suppression in DLD1 cells. Finally, the cytotoxic effect of simultaneous treatment with oxaliplatin and adriamycin(an inhibitor of a significantly downregulated gene after Girdin suppression in DLD1 cells) was examined by MTT assay.RESULTS: The most effective siRNA suppressed Girdinexpression with an inhibition efficiency of 57%. Compared with the scramble control, DLD1 cells infected with the Girdin shRNA displayed decreased Girdin mRNA and protein levels(P < 0.05), and Girdin knockdown significantly enhanced chemosensitivity to oxaliplatin in colorectal cancer cells(P < 0.05). Microarray data revealed that 381 and 162 genes were upregulated and downregulated in response to Girdin reduction, respectively, with ratios > 1.2 or < 0.8(P < 0.01). Interestingly, TOP2B(DNA topoisomerase 2-β) was downregulated(ratio = 0.78, P = 0.0001) and oxaliplatin/adriamycin combination resulted in increased cell death compared with treatments with individual agents(P < 0.05).CONCLUSION: Girdin knockdown enhances chemosensitivity of colorectal cancer cells to oxaliplatin via TOP2B down-regulation. These findings provide a promising approach to overcome the chemoresistance of colorectal cancer cells.

Ileal pouch anal anastomosis with modified double-stapled mucosectomy-the experience in China

AIM:To investigate the feasibility and long-term functional outcome of ileal pouch-anal anastomosis with modified double-stapled mucosectomy.METHODS:From January 2002 to March 2011,fourtyfive patients underwent ileal pouch anal anastomosis with modified double-stapled mucosectomy technique and the clinical data obtained for these patients were reviewed.RESULTS:Patients with ulcerative colitis(n = 29) and familial adenomatous polyposis(n = 16) underwent ileal pouch-anal anastomosis with modified doublestapled mucosectomy.Twenty-eight patients underwent one-stage restorative proctocolectomy,ileal pouch anal anastomosis,protective ileostomy and the ileostomy was closed 4-12 mo postoperatively.Two-stage procedures were performed in seventeen urgent patients,proctectomy and ileal pouch anal anastomosis were completed after previous colectomy with ileostomy.Morbidity within the first 30 d of surgery occurred in 10(22.2%) patients,all of them could be treated conservatively.During the median follow-up of 65 mo,mild to moderate anastomotic narrowing was occurred in 4 patients,one patient developed persistent anastomotic stricture and need surgical intervention.Thirtyfive percent of patients developed at least 1 episode of pouchitis.There was no incontinence in our patients,the median functional Oresland score was 6,3 and 2 after 1 year,2.5 years and 5 years respectively.Nearly half patients(44.4%) reported "moderate functioning",37.7% reported "good functioning",whereas in 17.7% of patients "poor functioning" was observed after 1 year.Five years later,79.2% of patients with good function,16.7% with moderate function,only 4.2% of patients with poor function.CONCLUSION:The results of ileal pouch anal anastomosis with modified double-stapled mucosectomy technique are promising,with a low complication rate and good long-term functional results.

The TLRs family expression in lesions and peripheral blood of patients with acne and their regulating effect on the synthesis of inflammatory mediators

Objective:To study the TLRs family expression in lesions and peripheral blood of patients with acne and their regulating effect on the synthesis of inflammatory mediators.Methods:A total of 60 patients with acne vulgaris who were treated in our hospital between June 2013 and July 2016 were selected as the acne group, and 48 patients with trauma who accepted debridement and suturing in our hospital during the same period were selected as the control group. The acne focus tissue and the skin tissue after debridement were collected to determine the expression of TLRs and inflammatory mediators, and the peripheral blood mononuclear cells were collected to determine the expression of TLRs.Results:TLR2 and TLR4 protein expression in skin tissue and peripheral blood mononuclear cells of acne group were significantly higher than those of control group while the TLR3, TLR5, TLR7 and TLR9 protein expression were not significantly different from those of control group;IL-1 , IL-1β, IL-8 and TNF-α levels in acne tissue with high TLR2 and TLR4 expression were significantly higher than those in acne tissue with low TLR2 and TLR4 expression.Conclusion: TLR2 and TLR4 are highly expressed in lesions and peripheral blood of patients with acne and have promoting effect on the synthesis of inflammatory mediators.

A review on Ti_(3)C_(2)T_(x)-based nanomaterials:synthesis and applications in gas and humidity sensors

Ti_(3)C_(2)T_(x),which is a novel two-dimensional(2 D)material,has received enormous interest in the field of sensor technology due to its large surface area,excellent electrical conductivity,and abundant active surface sites.In recent years,several Ti_(3)C_(2)T_(x)-based gases and humidity sensors have been developed and reported.In this review,we focus on the latest applications of Ti_(3)C_(2)T_(x)-based nanomaterials in gas and humidity sensors.First,the synthesis of Ti_(3)C_(2)T_(x) from the dangerous fluorine-containing etching process to the safe fluorine-free preparation method was discussed,and the structures of the Ti_(3)C_(2)T_(x) controlled by different delamination methods were also outlined.Subsequently,the functionalization of pristine Ti_(3)C_(2)T_(x) and composite strategies for enhancing its gas and humidity sensing performance were reviewed.In addition,the gas and humidity sensing mechanisms of sensors based on Ti_(3)C_(2)T_(x) were also summarized.Finally,the challenges and opportunities for the use of Ti_(3)C_(2)T_(x) gas and humidity sensors were discussed to provide guidance on the promising potential of Ti_(3)C_(2)T_(x) in this field.

Enhanced positive humidity sensitive behavior of p-reduced graphene oxide decorated with n-WS_(2) nanoparticles

Most resistance-type humidity sensors exhibit negative humidity sensitivity,i.e.,their resistance decreases with a corresponding increase in humidity.This is primarily attributed to the dominant role of ionic conduction in adsorbed water.In this work,a humidity sensor based on a p-type reduced graphene oxide(p-rGO)with positive humidity sensitivity is proposed.Moreover,its positive humidity sensing response is further enhanced by n-type WS_(2) nanoparticles modification.The results show that both rGO and r GO/WS_(2) humidity sensors have good linear response in the relative humidity(RH)range of0%-91.5%.The sensitivity of the rGO/WS_(2) humidity sensor is 1.87 times that of rGO humidity sensor,which is mainly attributed to p-n heterojunction between rGO and WS_(2).Besides,the r GO/WS_(2) humidity sensor has small humidity hysteresis(-3%RH)and good repeatability.This work demonstrates a humidity sensor based on rGO/WS_(2) composite film and provides a facile route for fabricating humidity sensor with positive humidity sensing properties.

Targeted mutagenesis in Arabidopsis thaliana using CRISPR-Casi2b/C2ci^°°

Casi2b/C2ci is a newly identified class 2 CRISPR endonuclease that was recently engineered for targeted genome editing in mammals and rice.To explore the potential applications of the CRISPR-Casi2b system in the dicot Arabidopsis thaliana,we selected BvCasi2b and BhCasi2b v4 for analysis.We successfully used both endonucleases to induce mutations,perform multiplex genome editing,and create large deletions at multiple loci.No significant mutations were detected at potential off-target sites.Analysis of the insertion/deletion frequencies and patterns of mutants generated via targeted gene mutagenesis highlighted the potential utility of CRISPRCasi2b systems for genome editing in Arabidopsis.