以Ni/ZSM-5为催化剂制备纳米碳质材料(英文)

以ZSM-5分子筛为模板担载金属镍(Ni/ZSM-5)为催化剂,在不同质量分数Ni和温度下进行气相化学沉积过程得到氢气和纳米碳质材料(碳纳米管、纳米炭纤维)。氢气和纳米碳质材料的产率随Ni质量分数增加和反应温度升高而显著地增加,但当Ni含量为8%时产率却减小。纳米碳质材料的形貌与反应温度密切相关。在较高温度下可沉积出碳纳米管,在较低温度下则可得到纳米炭纤维。随着反应时间的延长Ni/ZSM-5的催化活性降低。     

The preparation of TiO2–nitrogen doped by calcination of TiO2·xH2O under ammonia atmosphere for visible light photocatalysis

The investigation on incorporating nitrogen group into titanium dioxide in order to obtain powdered visible light-active photocatalysts is presented. The industrial hydrated amorphous titanium dioxide (TiO₂·xH₂O) obtained directly from sulphate technology installation was modified by heat treatment at temperatures of 100–800 °C for 4 h in an ammonia atmosphere. The photocatalysts were characterized by UV–VIS–DR and XRD techniques. The UV–VIS–DR spectra of the modified catalysts exhibited an additional maximum in the VIS region (, ) which may be due to the presence of nitrogen in TiO₂ structure. On the basis of XRD analysis it can be supposed that the presence of nitrogen does not have any influence on the transformation temperature of anatase to rutile. The photocatalytic activity of the modified photocatalysts was determined on the basis of decomposition rate of phenol and azo-dye (Reactive Red 198) under visible light irradiation. The highest rate of phenol degradation was obtained for catalysts calcinated at 700 °C (6.55%), and the highest rate of dye decomposition was found for catalysts calcinated at 500 and 600 °C (ca. 40–45%). The nitrogen doping during calcination under ammonia atmosphere is a very promising way of preparation of photocatalysts which could have a practical application in water treatment system under broader solar light spectrum.     

Methods of mycological analysis in buildings

Due to their properties and common occurrence, fungi constitute the most frequent cause of biodeterioration of building materials and a serious health hazard to occupants. The authors present the methods of mycological analysis used to assess contamination caused by moulds and their metabolites in buildings.     

Heterocyclic amines and azaarenes in pan-fried meat and its gravy fried without additives and in the presence of onion and garlic

The effect of onion and garlic on the formation of heterocyclic amines (HAs, aminoazaarenes) and azaarenes (aza-PAHs) was evaluated by comparing the concentrations of several compounds in meat and gravy samples, obtained from three pork dishes prepared in the presence and absence of these spices. The concentrations of individual HAs (8-MeIQx, MeIQ, 4,8-DiMeIQx, PhIP) were from 0.5 ng g⁻¹ to 10.5 ng g⁻¹ of meat and of azaarenes (benzo[a]acridine, benzo[c]acridine, dibenzo[a,c]acridine, dibenzo[a,j]acridine and dibenzo[a,h]acridine) – from 0.06 ng g⁻¹ to 0.99 ng g⁻¹. The addition of onion (30 g/100 g of meat) in the dishes investigated, caused a decrease in heterocyclic amines concentration (considering total contents in meat and gravy) in the range of 31–49% and of azaarenes by 21–48%. Garlic (15 g/100 g of meat) lowered the concentration of HAs by 26–36% and azaarenes by 33–40%; the changes in concentrations caused by these spices were different for particular compounds. Components of onion and garlic intensify the extraction of heterocyclic amines and azaarenes from meat in gravy.     

Porous microspheres,copolymers of bis[4‐(2‐hydroxy‐ 3‐methacryloyloxypropoxy)phenyl]sulfide,and divinylbenzene as stationary phase for HPLC

Synthesis of highly crosslinked methacrylate copolymers of in form of microspheres is presented. They are prepared from tetrafunctional methacrylate derivative of bis(4‐hydroxyphenyl)sulfide, bis[4‐(2‐hydroxy‐3‐methacryloyloxypropoxy)phenyl]sulfide (BES‐DM), and divinylbenzene (DVB). In chemical structure of these copolymers exhibit hydroxyl and ester groups of hydrophilic nature. Additionally, copolymer contains sulfur atoms coming from BES‐DM monomer. Porous structure of the copolymers in the dry and wet state was studied. Microspheres possessing the largest pore volume and specific surface area were subjected to chromatographic investigations. The results show that polar functional groups existing in the chemical structure of the studied microspheres have influence on reversed‐phase HPLC retention mechanism. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Acute Kidney Injury in COVID-19

COVID-19 is mainly considered a respiratory illness, but since SARS-CoV-2 uses the angiotensin converting enzyme 2 receptor (ACE2) to enter human cells, the kidney is also a target of the viral infection. Acute kidney injury (AKI) is the most alarming condition in COVID-19 patients. Recent studies have confirmed the direct entry of SARS-CoV-2 into the renal cells, namely podocytes and proximal tubular cells, but this is not the only pathomechanism of kidney damage. Hypovolemia, cytokine storm and collapsing glomerulopathy also play an important role. An increasing number of papers suggest a strong association between AKI development and higher mortality in COVID-19 patients, hence our interest in the matter. Although knowledge about the role of kidneys in SARS-CoV-2 infection is changing dynamically and is yet to be fully investigated, we present an insight into the possible pathomechanisms of AKI in COVID-19, its clinical features, risk factors, impact on hospitalization and possible ways for its management via renal replacement therapy.     

The Impact of Selected Bacterial Sexually Transmitted Diseases on Pregnancy and Female Fertility

Sexually transmitted infections (STIs) caused by Neisseria gonorrhoeae, Chlamydia trachomatis and Mycoplasma genitalium are a common cause of pelvic inflammatory disease (PID) which can lead to tubal factor infertility (TFI). TFI is one of the most common causes of infertility, accounting for 30% of female fertility problems. STIs can also have an impact on pregnancy, leading to adverse pregnancy outcomes. Escalating antibiotic resistance in Neisseria gonorrhoeae and Mycoplasma genitalium represents a significant problem and can be therapeutically challenging. We present a comprehensive review of the current treatment options, as well as the molecular approach to this subject. We have given special attention to molecular epidemiology, molecular diagnostics, current and new treatments, and drug resistance.     

Pore structure of carbons coated on ceramic particles

Pore structure of carbon coated on ceramic particles by carbonization of precursor in a powder mixture at 900 °C was studied by focusing on the effects of substrate ceramics (MgO, TiO₂ and various phases of Al₂O₃) and of carbon precursor (poly(vinyl alcohol) (PVA), poly(ethylene terephthalate) (PET) and hydroxyl propyl cellulose (HPC)). By dissolving substrate MgO particles, carbon coated was found to have a high BET surface area, more than 1000 m²/g, which was almost the same as the value estimated from apparent surface area measured on carbon-coated MgO particles under the assumption of zero surface area of the substrate. The carbon separated was found to be rich in micropores from the analyses by DFT method and α_s plot. The dependence of the BET surface area on the amount of carbon coated on TiO₂ with a high surface area was the same for three carbon precursors, although the carbon yields from the precursors were slightly different. Porous Al₂O₃ substrates, γ-Al₂O₃as-received and that formed from Al(OH)₃ during carbonization, gave a high BET surface area, but dense Al₂O₃, α-Al₂O₃, gave a low surface area.