Rational design of stratified material with spatially separated catalytic sites as an efficient overall water-splitting photocatalyst

The development of metal sulfide catalysts with remarkable activity toward efficient overall photocatalytic water splitting remains challenging owing to the dominant charge recombination and deficient catalytic active sites.Moreover,in the process of water oxidation catalysis,the inhibition of severe photocorrosion is an immense task,requiring effective photogenic hole-transfer kinetics.Herein,stratified Co-MnO_(2)@CdS/CoS hollow cubes with spatially separated catalytic sites were rationally designed and fabricated as highly efficient controllable catalysts for photocatalytic overall water splitting.The unique self-templated method,including a continuous anion/cation-exchange reaction,integrates a Co-doped oxidation co-catalyst(Co-MnO_(2))and a reduction co-catalyst(CoS)on the nanocubes with uniform interface contact and ultrathin two-dimensional(2D)nanometer sheets.We demonstrate that the stratified Co-MnO_(2)@CdS/CoS hollow cubes can provide an abundance of active sites for surface redox reactions and contribute to the separation and migration of the photoionization charge carriers.In particular,CoS nanoparticles dispersed on the walls of CdS hollow cubes were identified as reduction co-catalysts accelerating hydrogen generation,while Co-MnO_(2) nanosheets attached to the inner walls of the CdS hollow cube were oxidation co-catalysts,promoting oxygen evolution dynamics.Benefiting from the desirable structural and compositional advantages,optimized stratification of Co-MnO_(2)@CdS/CoS nanocubes provided a catalytic system devoid of precious metals,which exhibited a remarkable overall photocatalytic water-splitting rate(735.4(H_(2))and 361.1(O_(2))μmol h^(−1) g^(−1)),being among the highest values reported thus far for CdS-based catalysts.Moreover,an apparent quantum efficiency(AQE)of 1.32%was achieved for hydrogen evolution at 420 nm.This study emphasizes the importance of rational design on the structure and composition of photocatalysts for overall water splitting.

A case of resection of giant decidual polyp in first trimester

A 29-years-old primiparous woman,presented at 9 weeks 2 days pregnant due to moderate vaginal bleeding with neoplasm prolapsed from vagina for two days.She have suffered from recurrent vaginal spotting for about 4 weeks,and took dydrogesterone more than 3 weeks following the doctor's instructions at the local hospital.She had diagnosed as an endometrial polyp of about 1.3×0.6 cm in size by ultrasound scan before pregnancy.At present,the color doppler ultrasound revealed that a giant decidual polyp occupied the whole cervix canal,with wide pedicle base arised from the middle and lower part of the uterine cavity,and the lower part prolapsed the outside of cervix.After hospital admission,the speculum examination showed that a dark purple neoplasm with a size of about 5×3×3cm in the vagina protruding out of the cervical canal,on which surface there was a spontaneous bleeding point.The blood test findings included a WBC count of 8.59×910/L and C-reactive protein level of 3.02ng/L.Her temperature was 36.2℃.Cefuroxime was given to prevent infection after admission.Compression was given to stop bleeding,but there was still active bleeding on the surface of the polyp the next day.Therefore,a ultrasound-guided torsion polypectomy was performed in emergency.In the therter,we twisted the neoplastic tissues by oval forceps taking a step-by-step approach,until 1cm above the outsise of cervix.At this point,ultrasound scan showed that the pregnant sac was obviously pulled by external forces.So,we stop the polypectomy,leaving a small portion of the giant polyp.Ceftrixone sodium and dydrogesterone were given after the operation and a small amount of vaginal bleeding lasted for 6 days without obvious abdominal pain.A medium to strong echo of about 1.7×0.6×0.9cm in the cervical canal was showed by color doppler ultrasound,which continued upward to the upper part of the cervical os.Histopathological examination revealed a decidual polyp.The patient had no abdominal pain and vaginal bleeding during pregnancy.She had a premature rupture of membranes and gave birth to a baby with the weight of 3300g through vaginal at 37 weeks and 1 day of gestation.

Proteomic Analysis of the Serum of Patients with Stable Vitiligo and Progressive Vitiligo

To the Editor： Vitiligo is not a fatal disease; however, it can have strong social and psychological impacts on the patients. Genetic susceptibility, autoimmunity, neural dysregulation, melanin self-destruction, and oxidative stress may be involved in the pathogenesis of vitiligo.

Constructing interfacial electric field and Zn vacancy modulated ohmic junctions ZnS/NiS for photocatalytic H_(2) evolution

Adjusting the interfacial transport efficiency of photogenerated electrons and the free energy of hydrogen adsorption through interface engineering is an effective means of improving the photocatalytic activity of semiconductor photocatalysts.Herein,hollow ZnS/NiS nanocages with ohmic contacts containing Zn vacancy(V_(Zn)-ZnS/NiS)are synthesized using ZIF-8 as templates.An internal electric field is constructed by Fermi level flattening to form ohmic contacts,which increase donor density and accelerate electron transport at the V_(Zn)-ZnS/NiS interface.The experimental and DFT results show that the tight interface and V_(Zn) can rearrange electrons,resulting in a higher charge density at the interface,and optimizing the Gibbs free energy of hydrogen adsorption.The optimal hydrogen production activity of V_(Zn)-ZnS/NiS is 10,636 mmol h^(-1) g^(-1),which is 31.9 times that of V_(Zn)-ZnS.This study provides an idea for constructing sulfide heterojunctions with ohmic contacts and defects to achieve efficient photocatalytic hydrogen production.

Alterations of intestinal flora and the effects of probiotics in children with recurrent respiratory tract infection

Background Recurrent respiratory tract infection (RRTI) is a disease occurred frequently in preschool children.Methods A total of 120 RRTI children were randomly divided into active group,remission group,intervention group and control group,meanwhile 30 healthy children were selected as the healthy group.Children in the intervention group were given oral Bifidobaeterium tetravaccine tablets (Live) for 2 months,while the control group received routine treatment.Stool sample were detected to analyze the bacterial strains.The occurrence of respiratory tract infection (RTI) was compared between different groups during 1 year follow-up.Results Compared with the healthy group,the number of Bifidobacteria and Lactobacilli in the active group,remission group,intervention group and control group was significantly decreased (P < 0.05).The number of Bifidobacteria and Lactobacilli in the intervention group was significantly higher compared to other RRTI groups (P < 0.05).During the follow-up period,the average annual frequency of different acute RTI and use of antibiotics were significantly reduced (P < 0.05),the average duration of cough,fever and use of antibiotics at each episode were also significantly shortened (P < 0.05) in the intervention group compared to the control group.Conclusions Children with RRTI are susceptible to intestinal flora imbalance.Oral probiotics can effectively improve the RRTI intestinal microecological balance in children and reduce the frequency of RTI.