Humic acid-mediated visible-light degradation of phenol on phosphate-modified and Nafion-modified TiO_2 surfaces

Although humic acid(HA)can inhibit TiO2photocatalysis,it can sensitize TiO2and induce significant visible‐light(VL)activity in phenol degradation.This favorable effect of HA was negligible on phosphate‐modified TiO2(P‐TiO2),but significantly stronger on Nafion‐modified TiO2(Nf‐TiO2).The reaction rate constants for phenol degradation on Nf‐TiO2increased from(0.003±0.001)to(0.025±0.003)min?1when the reaction was performed in the presence of20mg/L HA.The different effects of HA on P‐TiO2and Nf‐TiO2photocatalysis cannot be attributed to adsorption changes,because the adsorption capacities of P‐TiO2and Nf‐TiO2were only slightly lower than that of TiO2at an initial HA concentration of20mg/mL.Scavenger tests,electron paramagnetic resonance spectroscopy,and H2O2detection were taken to understand the low VL activity of the P‐TiO2/HA suspension.The main active species for phenol degradation in the TiO2and Nf‐TiO2suspensions were superoxide radicals.There were negligible amounts of superoxide radicals in the P‐TiO2/HA suspension,possibly because a direct four‐electron oxygen reduction reaction occurred.The better VL activity of Nf‐TiO2was rationalized on the basis of Mott–Schottky and electrochemical impedance plots.Nafion modification resulted in cathodic shifts of the energy band positions,increased electron density,and less resistance to electron transfer across the interface between TiO2and electrolytes.All these factors facilitated electron transfer and improved the production of active species.Phosphate modification therefore did not improve the VL response of HA sensitized TiO2,and low concentrations of HA can facilitate VL photocatalytic degradation of organic pollutants on Nafion surface‐modified TiO2.

Physicochemical and Morphological Variation of Bamboo Cell Wall During Hydrothermal Pretreatment

Pretreatment is important for achieving high-value utilization of biomass.This study is conducted to evaluate the destruction of the Moso bamboo cell wall via hydrothermal pretreatment at different temperatures and pH values.Compositional and morphological analyses and subsequent enzymatic hydrolysis of the solid fractions indicate that the destruction of the cell wall,instead of the degradation or removal of hemicellulose and lignin,or the configuration transition of the cellulose crystal structure,is the most critical aspect for improving bioconversion efficiency.Although only an 8%-10%weight loss is incurred and similar crystalline indexes are achieved after mild hydrothermal treatments,the recovery of glucose is doubled,whereas the recovery of xylose from pretreated samples is approximately 35%.

Field Application of Mulberry Straw Arch in Ecological Bank Revetment

With the growing level of awareness and increasing demand for environmental protection,timber pile revetments with significant ecological effects have experienced increasingly wide application in China.The current timber pile revetment system has two problems:continuous dense piles have high construction costs and require large timber consumptions,while the discrete pile-bamboo fence systems have poor retaining effects.Considering these problems,an original revetment structure form is proposed:a discrete pile-mulberry straw arch structure.To investigate the mechanical properties of the mulberry straw,some mechanical tests are conducted on mulberry straw and its arch structure.It is found that the average compressive strength of mulberry straw is 2.30 MPa,the bending strength is 20.08 MPa and the shear strength is 2.99 MPa;considering the structural characteristics of arches,mulberry straw arches have a high bending strength,which affords immense potential for their application in revetment structures.Furthermore,by doing field study of the discrete timber pile-mulberry straw arch structure for bank revetment,it is found that the arch height of the mulberry straw arch changes 1.4–1.6 cm after 489 d observation.The soil settlement before the straw arch is 0.13–0.18 cm and the settlement of the pile is 0.66–0.72 mm.Compared with bamboo fence structure,the cost of using mulberry straw arch structure as revetment material can save up to 27.07%.Therefore,the discrete timber pile-mulberry straw arch has a rational and stable structure that provides effective support for protecting the riverbank and the toe of gentle slopes and effectively prevents the collapse of bank slopes in the rear.The new revetment structure proposed in this paper has signifi-cant ecological and economic effects,is easy to construct and feasible for standard production,and consequently has great application potential.

The Effect of Lignification Process on the Bioconversion Efficiency in Moso Bamboo

Recalcitrance of lignocellulosic biomass is closely related to the presence of lignin in secondary cell walls,which has a negative effect on enzyme digestibility,biomass-to-biofuels conversion,and chemical pulping.The lignification process and structural heterogeneity of the cell wall for various parts of moso bamboo were investigated.There were slight differences among three different column parts of moso bamboo in terms of chemical compositions,including cellulose,hemicelluloses,and lignin.However,the detailed analysis of the fractionated lignin indicated that the acid-soluble lignin was first biosynthesized,and the largest molecular weight value was detected from the bottom part of the moso bamboo,as well as the highest syringyl-to-guaiacyl ratio.Although the main b-O-4 aryl ethers and resinol structures were clearly present in all lignin samples examined by NMR analysis,the relatively small lignin biomacromolecule in the top part of the moso bamboo lead to poor thermal stability.For the bioconversion process,no significant difference was found among all the moso bamboo samples,and the relatively higher hydrolysis efficiency was largely dependent on the low crystallinity of cellulose rather than the degree of lignin biosynthesis.

Granulomatosis with polyangiitis presented as multiple cutaneous abscesses after hysterectomy

To the Editor:A 62-year-old woman presented to the dermatology department with a 5-month history of multiple painless cutaneous abscesses and ulcers[Figure 1A],occurring 1 month after a transvaginal hysterectomy due to uterine prolapse.Her general condition was good before and after the surgery,with no abnormal physical signs apart from metroptosis.She reported no fever,night sweat,cough,or abdominal pain,but 10 kg weight-loss.She has no history of diabetes,autoimmune diseases,or chronic infectious diseases.There was no similar illness in her family.

Clinical and histopathological predictors of rapid kidney function decline in patients with biopsy-proven diabetic kidney disease

To the Editor:Diabetic kidney disease(DKD)has become the leading cause of end-stage kidney disease(ESKD).According to the Kidney Disease Improving Global Outcomes(KDIGO)guidelines,rapid kidney function decline in DKD is defined as an estimated glomerular filtration rate(eGFR)slope≤−5 mL∙min^(−1)∙1.73 m^(−2)·year^(−1).The prognoses of patients who experience rapid eGFR decline are usually poor.In a multicenter retrospective study,230 of 377(61%)biopsy-proven DKD patients were rapid decliners.[1]It was reported that 32%and 42%of 195 type 2 diabetes(T2D)Pima Indians with normoalbuminuria and microalbuminuria,respectively,had a rapid eGFR decline,indicating that proteinuria alone has difficulty in fully predicting rapid kidney function decline in DKD patients with T2D.[2]Therefore,it is of interest to identify more useful clinicopathological predictors of a rapid kidney function decline in T2D patients.

德国资历框架内容体系的特点及启示

德国资历框架现已进入全面实施与评估阶段,其内容体系建设已较为完善。在德国资历框架建设的过程中逐渐在综合能力描述、职业资格与学历资格等值沟通、对现有教育体系影响边界等方面形成了自身特色。其框架中以综合能力为导向的学习成果描述、职业教育与普通教育等值不同类的论证、对现有教育领域内部资格体系的不可替代性,对德国资历框架确立建设基础、解决建设难点、设立建设边界等具有突出作用,也能为我国综合性资历框架构建提供有益的启示。