Greatly enhanced electro-optic modulation efficiency in titanium in-diffusion PIN-PMN-PT waveguide

Electro-optic modulators,which convert electrical signals onto the transmission light,are key devices in electro-optic modulating systems.Modulation efficiency is one of the most important parameters of an electro-optic modulator,which directly determines the footprint and power consumption of the device.Generally,modulation efficiency strongly depends on the electro-optic response of the crystal.The Pb(In_(1/2)Nb_(1/2))O_(3)-Pb(Mg_(1/3)Nb_(2/3))O_(3)-PbTiO_(3)(PIN-PMN-PT)single crystal with giant electro-optic coefficient(λ_(c))and high transparency indicates the potential to achieve greatly enhanced modulation efficiency.In this study,a prototype PIN-PMN-PT phase modulator was fabricated based on a titanium(Ti)in-diffusion waveguide,which is reported for the first time.The influences of titanium in-diffusion on the composition and domain structure of the PIN-PMN-PT single crystal were studied by transmission electron microscopy(TEM)and piezoelectric force microscopy(PFM),respectively.Finally,a half-wave voltage(V_(π))of 2.3 V was obtained using a device with 6-mm-long(L)electrodes.Furthermore,the electro-optic modulation efficiency(V_(π)L)was calculated as 1.38 V-cm,which was approximately one order of magnitude lower than that of commercial lithium niobate(LiNbO_(3),LN)phase modulators.Such enhanced modulation efficiency indicates more compact device and lower power consumption,which is of great significance for electro-optic modulation systems used in micro-fiber gyroscope,integrated photonic devices,etc.

Growth and metal uptake of energy sugarcane (Saccharum spp.) in different metal mine tailings with soil amendments

A pot experiment was conducted to investigate the feasibility of growing energy sugarcane （Sac- charum spp.） in three different metal mine railings （Cu, Sn and Pb/Zn tailings） amended with uncontaminated soil at different mixing ratios. The results indicated that sugarcane was highly tolerant to tailing environments. Amendments of 20% soil to Sn tailings and 30% soil to Cu tailings could increase the biomass of cane-stem for use as the raw material for bioethanol production. Heavy metals were mostly retained in roots, which indicated that sugarcane was useful for the stabilization of the tailings. Bagasse and juice, as the most valuable parts to produce bioethanol, only accounted for 0.6%- 3% and 0.6%-7% of the total metal content. Our study supported the potential use of sugarcane for tailing phytostabilization and bioenergy production.

Ceftazidime is a potential drug to inhibit SARS-CoV-2 infection in vitro by blocking spike protein-ACE2 interaction

Dear Editor,Coronavirus disease 2019(COVID-19)has spread globally as a severe pandemic,which is caused by a novel coronavirus named Severe Acute Respiratory Syndrome coronavirus 2(SARS-CoV-2).1 COVID-19 is a serious threat to healthcare systems,economies,and is devastating to some populations,such as the elderly and those with comorbidities.It is likely to coexist with human beings for a long time.Unfortunately,there is still no effective cure for COVID-19,especially the critically ill patients.

Laparoscopic management of benign splenic tumors in children

Background The splenic tumor is relatively rare in children.However,diagnosing and managing this disease remain controversial.This study aimed to evaluate the clinical characteristics and pathological features of benign splenic tumors and to explore the feasibility and safety of laparoscopic splenectomy in children.Methods The clinical data of all patients who were diagnosed with benign splenic tumors and admitted to our center between January 2014 and December 2020 were analyzed retrospectively.Factors that were documented included demographic criteria,clinical manifestations,preoperative examinations,surgical methods,histopathological characteristics,postoperative complications and outcomes.Results Totally,24 consecutive patients with a mean age of 10.21±2.59 years were operated laparoscopically.Nine patients presented with recurrent abdominal pain,vomiting or backache.The remaining 15 cases were asymptomatic and were identified incidentally.Laparoscopic total splenectomy(LTS)was performed in 12 cases,laparoscopic partial splenectomy(LPS)in 9 cases and deroofing of splenic cyst in 3 cases.No significant differences were observed in operation time,intraoperative bleeding and postoperative abdominal drainage between the LTS and LPS groups.Histopathology examination reported 12 cases of splenic epithelial cyst,5 cases of splenic lymphangioma or lymphatic malformation,3 cases of splenic hamartoma,3 cases of splenic littoral cell angioma and 1 case of splenic hemangioma.No postoperative complications and tumor recurrence were observed.Conclusions It is still difficult to precisely diagnose the splenic tumor preoperatively.Laparoscopic splenectomy is safe and feasible in treating the benign splenic tumors,and partial splenectomy is of great significance in preserving the immune function in children.

Rapid screening of SARS-CoV-2 inhibitors via ratiometric fluorescence of RBD–ACE2 complexes in living cells by competitive binding

To the Editor:The current coronavirus disease-19(COVID-19)pandemic spurs the development of antiviral drugs for SARS-CoV-2,as the number of patients with viral infections continues to rise globally in the context of widespread vaccination.Targeting the interaction between the receptor binding domain(RBD)of SARS-CoV-2 spike protein and the host cell ACE2 is a promising therapeutic strategy to effectively inhibit viral entry.

酿酒酵母THO-Sub2复合物的电镜结构及其防止R-loop积累和促进mRNA出核的功能研究

在真核生物转录过程中,新生成的RNA分子的成熟需要众多蛋白质的参与.其中,酿酒酵母THO复合物能够与转录活跃的染色质区域相结合,通过招募依赖于RNA的ATP水解酶Sub2,去除伴随转录过程形成的R-loop并促进m RNA的出核运输.本研究成功地在体外重构了酿酒酵母THO复合物,并运用单颗粒冷冻电镜技术分别解析了单独的THO复合物及其与Sub2结合状态下的近原子分辨率结构.在此结构的基础上,本研究通过突变关键氨基酸位点破坏THO和Sub2之间的相互作用,揭示了THO复合物招募Sub2的分子机制.此外,本研究结合分子动力学模拟、染色质免疫沉淀和免疫荧光等技术手段,阐述了THO-Sub2复合物防止转录过程中R-loop结构的积累以及确保基因组稳定性和促进m RNA出核的分子机制.

Distinct chemokines selectively induce HIV-1 gp120-integrinα4β7 binding via triggering conformer-specific activation ofα4β7

Dear Editor,Gut associated lymphoid tissue(GALT)is the principal site where human immunodeficiency virus 1(HIV-1)replicates.CD4^(+) T cells residing in GALT are predominant targets of HIV-1 during the acute phase of infection.CD4^(+) T cells expressing a high level of gut-homing receptor integrin α4β7 are more susceptible to productive infection by HIV-1.

Correction To:Ceftazidime is a potential drug to inhibit SARS-CoV-2 infection in vitro by blocking spike protein-ACE2 interaction

After online publication of the article1 we noticed an error in citations for affiliation in the supplementary materials published in this article.The citations for affiliation in the article were reordered during the production process to match the order of authors in the author group.Unfortunately,this was not reflected in the supplementary material.

Laparoscopic surgery for congenital biliary dilatation accompanied by accessory hepatic ducts:a report of seven cases

Congenital biliary dilatation(CBD)is a congenital biliary tract anomaly characterized by expansion of the common bile duct and is thus known clinically as a choledochal cyst.The form of CBD varies,and the commonly used clinical classification was described by Todani et al.1 Pancreaticobiliary maljunc-tion is reported to be present in 30%-96%of patients with CBD.23 The main aims of laparoscopic surgery include resection of the dilated biliary ducts,gallbladder,pancreatic-bile diversion,and biliary tract reconstruc-tion.

Cholesterol modulating the orientation of His17 in hepatitis C virus p7 (5a) viroporin--A molecular dynamic simulation study

Protein p7 of HCV is a 63 amino acid channel forming membrane protein essential for the progression ofviral infection and the sensitivity of this channel to small-molecule inhibitors renders p7 a potentialtarget for novel therapies against HCV infection. Previous biochemical experiments suggested that theHis17 of p7 is a pore-lining residue and solvated-exposed to participate in channel gating. However, arecent NMR structural identification of the p7 hexamer in dodecylphosphocholine （DPC） micellesindicated that the His17 is embedded into the protein matrix. In this work, we performed moleculardynamic simulations to bridge the controversial observations. Our results illustrated that byincorporating the cholesterol into DOPC membranes to mimic an actual membrane-like composition,the orientation of His17 in the hexameric bundles spontaneously access to the central pore region,indicating a versatile property of the p7 viroporin conformation that could be voluntarily influenced byits surrounding environments.