Supercritical transesterification of vegetable oil and ethanol: temperature and residence time effects on phase formation and water content

Supercritical transesterification has emerged as a readily available alternative for biodiesel production since no catalyst is required, thereby generating fewer waste products. In this research, the supercritical transesterification of refined vegetable oil and aqueous ethanol was carried out at temperatures 400 to 480 °C and a 12:1 ethanol to oil molar ratio, to assess the effect of temperature and residence time in the formation of a homogeneous phase, effluent appearance and increased water content derived from glycerol etherification. The results showed that water was produced at temperatures higher than 400 °C, as expected from the occurrence of glycerol etherification, and that prolonged times resulted in gas and soot formation, indicating esters decomposition. Through water mass balances, it was possible to identify the set of operation conditions in which the water formed from glycerol etherification matched with the maximum expected according to the proposed reaction scheme.

La transesterificación supercrítica se ha propuesto como una alternativa para la producción de biodiesel ya que no requiere catalizador de esta manera se generan menos residuos. En esta investigación, la transesterificación supercrítica de aceite vegetal refinado y etanol acuoso se llevó a cabo a temperaturas en el rango 400 a 480 °C y relación molar etanol a aceite de 12:1, para evaluar el efecto de la temperatura y el tiempo de residencia en la formación de una fase homogénea, apariencia del efluente e incremento del contenido de agua resultado de las reacciones de eterificación del glicerol. Los resultados mostraron que se produjo agua a temperaturas mayores a 400°C, atribuida a la eterificación del glicerol, y que tiempos de residencia prolongados resultaron en formación de gas y hollín, indicativo de reacciones de descomposición de esteres. A través de balances de masa, fue posible identificar el conjunto de condiciones de operación a las cuales el agua formada por la eterificación del glicerol coincide con el valor máximo esperado de acuerdo con el esquema de reacción propuesto.

A transesterificação supercrítica foi proposta como uma alternativa para a produção de biodiesel porque não requer catalisador e, dessa forma, gera menos resíduos. Nesta pesquisa, a transesterificação supercrítica de aceite vegetal refinado e etanol acuoso foi conduzida a temperaturas entre 400 e 480 °C e uma relação molar de etanol e aceite de 12: 1, para avaliar o efeito da temperatura e do tempo de residência na formação de uma fase homogênea, apariência do efluente e aumento do conteúdo de água resultante das reações de eterificação do glicerol. Os resultados mostraram que se produziu água a temperaturas maiores que 400°C, atribuída à eterificação do glicerol, e que os tempos de residência prolongados resultaram na formação de gás e hollín, indicativo de reações de decomposição de ésteres. Por meio de balanças de massa, foi possível identificar o conjunto de condições de operação em que a água formada pela eterificação do glicerol coincide com o valor máximo esperado de acordo com o esquema de reação proposto.

Analysis of motivating factors for eye donation among families of eye donors in South India – A questionnaire-based study

Purpose: To report the factors influencing eye donation among families of successful eye donors in India. Methods: The consenting family members of 434 deceased individuals who donated eyes between April 2019 and March 2020 were retrospectively interviewed via a telephonic questionnaire survey. Details regarding the donors and their families, motivating factors for eye donation, and time taken for tissue recovery were collected and analyzed. Results: The mean age of donors was 66.8 years, and only 13.9% of them had pledged to donate their eyes before death. For 62.3% of donations, children of donors were the primary consenters for eye donation. In 18.8% of donors, there was a previous history of eye donation in the family. Many donations were motivated by a non?governmental organization volunteer (40.5%) or by a grief counselor at the hospital (27.4%). Hospital?based corneal retrieval programs and donations where the first eye bank contact was made through hospital personnel had the greatest percentage of rapid enucleations (performed within 3 h after death) (48.7% and 49.1%, respectively; P = 0.001 and P = 0.02, respectively). Conclusion: Children of donors, typically in the working?age group, most often make the decision for donation, and hence, future awareness programs should focus on this specific population. All types of hospitals should advocate for eye donation as they are a common point of contact for a grieving family, and health?care professionals at all levels should be considered for training as motivators for eye donation.

Use of X-Ray Photoelectron Spectroscopy as an analytical tool for the study of contamination by Teflon in the synthesis of Mo(VI)Cl2O2Bipy/ TiO2 catalysts

The preparation of catalysts can involve various sources of contamination, which can seriously affect the quality of the prepared materials. In the present work, a case of fluorine contamination in a set of catalyst samples was studied, in which using the X-Ray Photoelectron Spectroscopy (XPS) technique, it was evidenced by the F 1s signal that this element was present in the form of Teflon, since its binding energy corresponded mainly to the CF2 species. Furthermore, using the C 1s signal, it was also possible to corroborate the presence of the CF2 group, which is associated with the main component of the Teflon carbon chains. The use of this information made it possible to identify that the solvent dehydration procedure (previous step to obtaining the catalysts) could lead to contamination with Teflon since it involved various accessories with Teflon, organic solvents and high temperature; the Teflon tape and the magnetic stirrer being the possible sources of contamination.

La preparación de catalizadores puede contener diversas fuentes de contaminación, las cuales pueden afectar seriamente las propiedades de los materiales preparados. En este artículo se estudió un caso de contaminación con flúor en una serie de muestras de catalizadores. Empleando la técnica de espectroscopia fotoelectrónica de rayos X (XPS) se evidenció la presencia de flúor en la superficie de los materiales, el cual estaba asociado al polímero teflón, ya que su energía de enlace correspondía principalmente con la de la especie CF2. Además, empleando la señal C 1s, se logró corroborar la presencia de la especie CF2, el cual está asociado al componente principal de las cadenas carbonadas de teflón. El uso de la información obtenida por XPS permitió determinar que durante la deshidratación del solvente (paso previo para la obtención de los catalizadores en el cual se emplean solventes orgánicos y alta temperatura) se podría estar llevando a cabo la contaminación con teflón, ya que este componente está presente en diversos accesorios empleados en el proceso de deshidratación, siendo la cinta de teflón y el agitador magnético las posibles fuentes de contaminación.

A preparação de catalisadores pode conter diversas fontes de contaminação, as quais podem afeitar seriamente as propriedades dos materiais preparados. No presente trabalho estudou-se um caso de contaminação com flúor numa série de amostras de catalisadores. Usando a técnica da espectroscopia fotoeletrônica de raios X (XPS), evidenciou-se a presença de flúor na superfície dos materiais, o qual estava associado ao polímero Teflon, já que sua energia de ligação correspondia principalmente à da espécie CF2. Além disso, usando a sinal C 1s, foi possível corroborar a presença do grupo CF2, o qual está associado ao componente principal das cadeias carbônicas do Teflon. O uso da informação obtida por XPS permitiu determinar que durante a desidratação do solvente (passo prévio para a obtenção dos catalisadores no qual são usados solventes orgânicos e alta temperatura) tem-se a contaminação com Teflon, já que este componente está presente em diversos acessórios utilizados no processo de desidratação, sendo a fita do Teflon e o agitador magnético as possíveis fontes da contaminação.

Hibiscus tiliaceus mediated phytochemical reduction of zinc oxide nanoparticles and emonstration of their antibacterial, anticancer, and dye degradation capabilities

The present research focused on the green, non-toxic, low-cost synthesis of zinc oxide nanoparticles (ZnO NPs) using aqueous extract of Hibiscus tiliaceus leaves as a reducing and stabilizing agent. Thus, synthesized ZnO NPs were characterized by nanotechnological applications, i.e., ultraviolet-visible spectroscopy (UV-vis), dynamic light scattering (DLS), zeta potential, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and high-resolution transmission electron microscopy (HR-TEM). The nanotechnological applications showed that as-synthesized ZnO NPs have bandgap energy of 2.97 eV, zeta potential of ?1.2 mV, crystalline in nature (JCPDS data card no-89-1397), and an average size of 30 to 60 nm. The FTIR showed that ZnO NPs have coated with plant secondary metabolites and assisted in the process of green synthesis. The ZnO NPs exhibited broad-spectrum antibacterial activity on Gram-positive and Gram-negative bacteria. The ZnO NPs showed potential anticancer activity against human breast cancer cells MCF-7 and determined the IC50 value as 65.83 ± 2.57 µg/mL by MTT assay. Furthermore, ZnO NPs were used as nano-catalyst for dye degradation of methylene blue, methyl orange, and malachite green with NABH4 as a reducing agent. The ZnO NPs exhibited potent dye degradation capability and followed pseudo-first order kinetics. The study concluded that ZnO NPs could be highly useful as anticancer and antibacterial agents in the biomedical field, and as an environmental cleaning agent for dye degradation in textile industries.

Incorporation of a polymerization catalyst for improved mechanical behavior and physicochemical characteristics of a light-cured pulp capping material / Incorporação de um catalisador de polimerização para aprimorar propriedades mecânicas e fisíco-químicas de um protetor pulpar fotoativável

Objective: To evaluate the influence of the incorporation of a polymerization catalyst to a light-cured pulp capping material on mechanical behavior and physicochemical characteristics. Material and Methods: Different percentages (2 wt%, and 4 wt%) of diphenyliodonium hexafluorophosphate (DPI) were incorporated into the Ultra-Blend Plus, a resin-modified calcium-based cement. The material without incorporation of DPI (0 wt%) served as control. Degree of Conversion (DC), Flexural Strength (FS), Elastic Modulus (EM), Water Sorption (WSp), Solubility (Sl), and pH of eluate at 24-h, 72-h, and 7-day storage times were measured. One-way ANOVA/Tukey posthoc tests were used to analyze the data (p <0.05). Results: For DC, FS, and EM, materials with different % of DPI showed statistically significant differences, so that 0% provided the lowest values and 2% the highest values. Materials with 0% and 2% of DPI provided statistically the lowest WSp, whilst material with 0% of DPI showed statistically the highest Sl. Conclusion: All materials provided statistically similar pH to eluates regardless of storage time, although only materials with DPI at 2% and 4% maintained pH of eluates statistically similar from 72 h to 7 days storage times.(AU)

Objetivo: avaliar a influência nas propriedades mecânicas e físico-químicas da incorporação de um catalisador de polimerização a um protetor pulpar fotoativável. Material e Métodos: foram adicionadas diferentes porcentagens em massa (2% e 4%) de hexafluorofosfato de difeniliodônio (DPI) ao Ultra-Blend Plus, um cimento à base de hidróxido de cálcio modificado por resina. O material sem a adição do DPI (0%) serviu como controle. Foram avaliados: Grau de Conversão (DC), Resistência Flexural (FS), Módulo de Elasticidade (EM), Sorção (WSp), Solubilidade (SI) e o pH do eluato nos tempos de 24h, 72h e 7 dias de armazenamento. ANOVA 1-way com pós-teste de Tukey (p <0.05). Foi utilizado para avaliar os resultados estatisticamente. Resultados: Os materiais com diferentes % de DPI apresentaram diferenças significativas para os testes de DC, FS e EM. A porcentagem em massa de 0% de DPI mostrou valores inferiores a todos os testados e os materiais com adição 2% apresentaram a melhor performance. Materiais com 0% e 2% de DPI apresentaram valores inferiores de WSp; a porcentagem de 0% proporcionou valores estatisticamente maiores para SI. Conclusão: Todos os materiais testados apresentaram pH semelhante nos eluatos independente do tempo de armazenamento, contudo, apenas os materiais com 2% e 4% mantiveram o pH dos eluatos estatisticamente similares nos tempos de estocagem de 72h a 7 dias.(AU)

Por um método niseano na saúde mental: a construção de um ateliê de arte na emergência psiquiátrica / Towards a nisean method in mental health: the creation of an art studio in a psychiatric emergency / Por un método niseano en salud mental: la construcción de un estudio de arte en emergencias psiquiátricas

O presente artigo relata a experiência da intervenção artística proposta pelo Programa de Residência de Psicologia em Saúde Mental do Hospital Psiquiátrico Ulysses Pernambucano (HUP) e Universidade de Pernambuco, na cidade de Recife, em Pernambuco. Desde 2019, viemos somando forças para a criação de um ateliê de arte dentro da emergência psiquiátrica, buscando atualizar o método de Nise da Silveira na atenção à crise em saúde mental. No percurso metodológico, escolhemos o paradigma junguiano como fundamento de nossas reflexões articuladas a partir do Relato de Experiência. Imersas nas obras da Dra. Nise e nas imagens produzidas no ateliê de arte do HUP, defendemos que existe um método niseano que precisa ser mais bem conhecido e disseminado nos serviços de saúde mental. O trabalho realizado por Nise da Silveira segue inovador no cuidado aos "inumeráveis estados do ser", sendo importante de ser resgatado no avanço da Reforma Psiquiátrica e no desenvolvimento da teoria junguiana.

This article presents the experience of an artistic intervention proposed by the Psychology Residency Program in Mental Health at the Ulysses Pernambucano Psychiatric Hospital (HUP) and the University of Pernambuco (UPE) in the city of Recife, Pernambuco, Brazil. Since 2019, we have joined forces to create an art studio in the hospital's psychiatric emergency ward, in an effort to update Nise da Silveira's method of responding to mental health crises. For our methodology, we chose the Jungian paradigm to support our reflections in this experience report. Immersed in the work of Dr. Nise and in the images produced at the HUP art studio, we affirm that a Nisean method should be better known and disseminated among mental health services. Nise da Silveira's work remains innovative in the care of the "countless states of being" and should be revised for the advancement of the Psychiatric Reform and the development of Jungian theory.

Este artículo relata la experiencia de la intervención artística propuesta por el Programa de Residencia en Psicología en Salud Mental del Hospital Psiquiátrico Ulysses Pernambucano (HUP) y la Universidad de Pernambuco, en la ciudad de Recife, PE. Desde 2019, hemos unido fuerzas para crear un estudio de arte dentro de la emergencia psiquiátrica, buscando actualizar el método de Nise da Silveira para abordar la crisis de salud mental. En el camino metodológico, elegimos el paradigma junguiano como fundamento de nuestras reflexiones articuladas desde el Informe de Experiencia. Inmersas en la obra del Dr. Nise y en las imágenes producidas en el estudio de arte del HUP, defendemos que existe un método niseano que necesita ser más conocido y difundido en los servicios de salud mental. El trabajo realizado por Nise da Silveira sigue innovador en el cuidado a los "innumerables estados del ser", siendo importante de ser rescatado en el avance de la Reforma Psiquiátrica y en el desarrollo de la teoría junguiana. El trabajo realizado por Nise da Silveira sigue siendo innovador en el cuidado de los "innumerables estados del ser", siendo importante rescatarlo en el avance de la Reforma Psiquiátrica y en el desarrollo de la teoría junguiana.

Production of L-2-aminobutyric acid from L-threonine using a trienzyme cascade / 生物工程学报

L-2-aminobutyric acid (L-ABA) is an important chemical raw material and chiral pharmaceutical intermediate. The aim of this study was to develop an efficient method for L-ABA production from L-threonine using a trienzyme cascade route with Threonine deaminase (TD) from Escherichia. coli, Leucine dehydrogenase (LDH) from Bacillus thuringiensis and Formate dehydrogenase (FDH) from Candida boidinii. In order to simplify the production process, the activity ratio of TD, LDH and FDH was 1:1:0.2 after combining different activity ratios in the system in vitro. The above ratio was achieved in the recombinant strain E. coli 3FT+L. Moreover, the transformation conditions were optimized. Finally, we achieved L-ABA production of 68.5 g/L with a conversion rate of 99.0% for 12 h in a 30-L bioreactor by whole-cell catalyst. The environmentally safe and efficient process route represents a promising strategy for large-scale L-ABA production in the future.

Effect of Process Variables on the Transesterification Process of Palm Oil Sludge to Biodiesel

In this research work, the optimum process variables (catalyst, methanol to oil ratio and reaction time) for transesterification of palm oil sludge (POS) to biodiesel were studied. The transesterification process was carried by mixture of palm oil sludge, methanol and catalyst with the help of magnetic stirrer at 300 rpm and at temperature of 60ºC. The catalyst used for the process was potassium hydroxide (KOH). One-Factor-at-A-Time was used to select the possible optimum levels of process variable that gives high biodiesel yield. The study was evaluated by five levels of methanol-to-oil ratio (1:1 – 12:1), catalyst (0.1- 2%) and reaction time (30 – 150 min).The optimum process variables for transesterification of palm oil sludge (POS) to achieved maximum biodiesel yield were found to be methanol to oil molar ratio of 12:1, catalyst loading of 1.5wt% and reaction time of 30 min. At this optimum conditions the maximum biodiesel yield was 61.2%. The biodiesel produced from transesterification of palm oil sludge was characterized in order to determine the properties of the product. The density of POS is 857.0 kg/m3, kinematic viscosity of 5.38 mm2/s, flash point of 180°C, pour point of -5°C, and Acid value of 0.17 mgKOH/g. The biodiesel produced from transesterification of palm oil sludge meets the EN 14214 and ASTM 6751 standard. Thus, this study will be helpful to determine an efficient and economical procedure for biodiesel production from non-edible raw materials with high free fatty acid.

Comparison of setup accuracy between Catalyst HD and skin markers in stereotactic body radiotherapy of lung cancer / 中华放射肿瘤学杂志

Objective@#To compare the setup accuracy between Catalyst HD and skin markers in stereotactic body radiotherapy (SBRT) of lung cancer.@*Methods@#A total of 24 cases treated with SBRT were selected and all patients were fixed with vacuum pad in the supine position. Patients in group A were positioned by Catalyst HD and those in group B were positioned by shin markers. All patients were matched with the CT images after CBCT scan by rigid registration and the setup errors in six directions (x-, y-, z-axis, Rtn, Pitch and Roll) were obtained.@*Results@#The mean±SD in group A and B in the six directions were as follows: (0.13±0.12) cm, (0.25± 0.19) cm; (0.26±0.15) cm, (0.13±0.11) cm; (0.23±0.19) cm, (0.35±0.29) cm; (0.43°±0.40°), (0.80°±0.69°); (0.48°±0.47°), (0.79°±0.64°); (0.62°±0.60°) and (0.88°±0.70°), respectively. Except the x-axis data in group B, all the data in the six directions were not normally distributed. The obtained data significantly differed between two groups (all P<0.05). The out-of-tolerance errors (>0.5 cm/2°) also significantly differed between two groups (P<0.05).@*Conclusions@#The setup errors of Catalyst HD are less than those of the skin markers (except the y-axis). The setup accuracy of Catalyst HD is superior to that of traditional skin markers, which is worthy of application in clinical practice.

Comparison of setup accuracy between Catalyst HD and skin markers in stereotactic body radiotherapy of lung cancer / 中华放射肿瘤学杂志

Objective To compare the setup accuracy between Catalyst HD and skin markers in stereotactic body radiotherapy (SBRT) of lung cancer.Methods A total of 24 cases treated with SBRT were selected and all patients were fixed with vacuum pad in the supine position.Patients in group A were positioned by Catalyst HD and those in group B were positioned by shin markers.All patients were matched with the CT images after CBCT scan by rigid registration and the setup errors in six directions (x-,y-,z-axis,Rtn,Pitch and Roll) were obtained.Results The mean ±SD in group A and B in the six directions were as follows:(0.13±0.12) cm,(0.25± 0.19) cm;(0.26±0.15) cm,(0.13±0.11) cm;(0.23±0.19) cm,(0.35±0.29) cm;(0.43°±0.40°),(0.80°±0.69°);(0.48°±0.47°),(0.79°±0.64°);(0.62°±0.60°) and (0.88°±0.70°),respectively.Except the x-axis data in group B,all the data in the six directions were not normally distributed.The obtained data significantly differed between two groups (all P＜0.05).The out-of-tolerance errors (＞0.5 cm/2°) also significantly differed between two groups (P＜0.05).Conclusions The setup errors of Catalyst HD are less than those of the skin markers (except the y-axis).The setup accuracy of Catalyst HD is superior to that of traditional skin markers,which is worthy of application in clinical practice.

Clinical application of Catalyst system in cervical cancer radiotherapy / 中华放射肿瘤学杂志

Objective To evaluate the clinical application of Catalyst system in positioning patients during cervical cancer radiotherapy,and to analyze its correlation with the bladder volume and body mass index (BMI) of patients.Methods A total of 33 patients diagnosed with cervical cancer from July to December 2017 in our hospital were included in the study.All patients were auxiliary positioned by an optical surface imaging system (C-Pad Catalyst) before each treatment.The CBCT imaging was executed twice a week.The setup errors from Catalyst and CBCT in the anterior-posterior (AP),superior-inferior (SI) and leg-fight (LR) directions were recorded.Each patient's bladder volume and BMI were also recorded.Results The setup errors between Catalyst with masks and CBCT had the significant difference in SI (P＜0.05) and LR (P＜0.05).For Catalyst without masks,the setup errors with the bladder volume of 200-300 ml had the significant association in SI (R=-0.316,P＜0.05).For the bladder volume of＞300 ml,the setup errors for Catalyst with masks had the significant association in AP (R=-0.493,P＜0.05),and that without masks had the significant association in SI and LR (R=0.335,P＜0.05,R=-0.348,P＜0.05).For patients of＜25 kg/m2,setup errors for Catalyst with masks had the significant association with the BMI in LR (R=0.197,P＜0.05);for ≥ 25 kg/m2,that with masks had the significant association in AP and SI (R =0.818,P＜0.05;R=-0.498,P＜0.05),that without masks had the significant association in AP and LR (R=0.652,P＜0.05;R=-0.558,P＜0.05).Conclusion Unlike CBCT system,the patient positioning by Catalyst system was easily affected by the bladder volume and BMI of patients.

Fruit Enzymes And Their Application: A Review

The pulp and periodontium have embryonic, anatomic and functional inter-relationships. The simultaneous exist-ence of pulpal problems and inflammatory periodontal disease can complicate diagnosis and treatment planning. This case report evaluates the efficacy of G-Bone graft in the management of vertical bone loss associated with an endo-perio lesion in a left mandibular first molar and second molar. A 40 year-old male patient with an endo-perio lesion in the left mandibular first and second molars was initially treated with endodontic therapy. Following the en-dodontic treatment, the defect was treated using G-Bone graft. At the end of 6 months, there was a gain in the clini-cal attachment level and reduction in probing depth. Radiographic evidence showed that there was a significant bony fill.

Catalyst system in patient positioning during breast cancer radiotherapy: clinical application and influencing factors / 中华放射肿瘤学杂志

Objective To evaluate the clinical application of Catalyst system in patient positioning during breast cancer radiotherapy,and to analyze its correlation with age and body mass index (BMI).Methods Twenty-four patients with breast cancer who were admitted to our hospital from May to August,2016 were enrolled as subjects.For all patients,auxiliary positioning was made by the optical surface imaging system (CRad Catalyst) before each treatment.The kV-kV imaging was executed weekly to verify positioning.Age,BMI,and setup errors of the two systems in the anterior-posterior (AP),superior-inferior (SI),and left-fight (LR) directions were recorded and analyzed by independent samples t-test and Pearson correlation analysis.Results The C-Rad Catalyst system had a significantly larger setup error in the AP direction than the kV-kV imaging (0.22±0.17 vs.0.18±0.13 cm,P＜0.05).There were no significant differences in setup errors in the SI or LR direction between the two systems (0.23±0.18 vs.0.19±0.15 cm,P＞0.05;0.28±0.28 vs.0.20±0.15 cm,P＞ 0.05).Age and BMI of patients had significant impacts on the C-Rad Catalyst system but the kV-kV imaging (P＞0.05):there were significant differences in setup errors in the AP and SI directions between patients ≤44 years of age and those 45-59 years of age (all P＜0.05);there were significant differences in setup errors in the AP and LR directions between patients ≤44 years of age and those ≥60 years of age (all P＜0.05);there was a significant difference in setup error in the LR direction between patients 45-59 years of age and those ≥ 60 years of age (P＜0.05);there was a significant difference in setup error in the SI direction between patients with BMIs of＜ 25 and ≥ 25 kg/m2 (P＜ 0.05).For patients ≥ 60 years of age,setup error of the C-Rad Catalyst system in the SI direction was correlated with age (r=-0.496,P＜0.05).For patients with BMI of＜25 kg/m2,setup error of the C-Rad Catalyst system in the AP direction was correlated with BMI (r=-0.445,P＜ 0.05).For patients with a BMI of ≥ 25 kg/m2,setup error of the C-Rad Catalyst system in the SI direction was correlated with BMI (r=-0.252,P＜0.05).Conclusions There is significant difference in setup error in the AP direction between the C-Rad Catalyst system and the kV-kV imaging.Age and BMI have impacts on patient positioning by the C-Rad Catalyst system.

Preparation and Properties of Tremella-like Fe-N-C Composite Catalyst for Oxygen Reduction Reaction / 分析化学

The Fe-N-C composite catalyst was prepared by the thermal decomposition of the chelate precursors based on Fe central ions and o-phenylenediamine ligands.It was observed from the scanning electron microscopy that the crumpled carbon micro-and nano-sheets were intertwined to form a free-standing tremella-like 3D structure.The N2 adsorption/desorption experiments revealed that the composite contained ample micro-and meso-pores and had a specific surface area of 290 m2/g.Graphitic C and multi-crystal Fe3C as main components were confirmed by the X-ray diffraction, and N-doping in the general form of graphite N and pyridine N was also verified by X-ray photoelectron spectroscopy.The electrochemical measurement showed that the tremella-like Fe-N-C composite catalyzed oxygen reduction through a four-electron path in an alkaline solution, and its activity was comparable to the commercial Pt/C catalyst.After 2000 cycles, the limited current density of the Fe-N-C catalytic electrode only decreased less than 5%, and the half-wave potential shift negatively 5 mV, which suggested that the Fe-N-C composite catalyst had better catalytic stability than the commercially used Pt/C catalyst.

On-line Matrix Elimination-ion Chromatography for Determination of Residual TEAB in Clopidogrel Sulfate / 中国药学杂志

OBJECTIVE: To establish a method of on-line matrix elimination together with ion chromatographic for determination of residual tetraethylammonium bromibde(TEAB) which acts as phase transfer catalyst in clopidogrel sulfate. METHODS: An ion excluding column Dionex IonPac NG1 was used for the separation of TEAB from clopidogrel sulfate, using 20 mmol·L-1 MSA as eluent. A pre-concentration column Dionex CG17 was used to enrich the trace TEAB. After being switched to analytical system, the separation was performed on Dionex ICS3000 using Dionex IonPac CS17 as analytical column, and suppressor was not required. 5 mmol·L-1 MSA containing 35% acetonitrile was used as mobile phase. RESULTS: The RSDs of retention time and peak area were good. The recoveries of TEAB were between 97.8%-103.3%. The calibration curves of analytes were linear in the range between 0.4 and 10.0 μg·mL-1. The limit of detection reached 0.2 μg·mL-1. CONCLUSION: This method can be applied to detect trace kation in pharmaceutical chemicals.

Asymmetric oxidation synthesis of esomeprazole sodium:research advances / 国际药学研究杂志

Esomeprazole sodium is a widely used proton pump inhibitor which is mainly applied to the treatment of gastric ul-cer,duodenal ulcer,digestive esophagitis and gastritis. By reviewing the literature over the past decade on the asymmetric oxidation of esomeprazole sodium ,the paper summarizes the synthetic process and focuses on the comparison of the critical steps. To choose suit-able chiral catalyst to reduce the cost of synthesis of esomeprazole sodium,this paper compares beyond the yield,enantioselectivity and other aspects. The conclusion is that the catalysts used in the most of oxidation systems are with a large load and high cost ,and compared with the classical Kagan-Modena system,the Ti-salan catalyst has advantages in the synthesis of esomeprazole sodium,and can be widely used.

Whole-cell biotransformation for simultaneous synthesis of L-2-aminobutyric acid and D-gluconic acid in recombinant Escherichia coli / 生物工程学报

A whole-cell catalyst using Escherichia coli BL21(DE3) as a host, expressing L- threonine dehydratase from Escherichia coli, and co-expressing leucine dehydrogenase from Bacillus cereus and glucose dehydrogenase from Bacillus subtilis for cofactor regeneration, was constructed and used for one-pot production of L-2-aminobutyric acid (L-ABA) and D- gluconic acid from L-threonine and D-glucose. We used shake-flask culture to study the whole-cell catalytic condition including temperature, pH, proper permeabilization of cells and optimal wet cells amount. Moreover, the whole-cell catalyst was cultured in 5-L fermentor by fed-batch fermentation, and 164 g/L L-threonine and 248 g/L D-glucose were converted to 141.6 g/L L-ABA and 269.4 g/L D-gluconic acid. The whole-cell catalyst is promising to fulfill industrial requirements for L-ABA and D-gluconic acid.

Effect of titanium powder on the bond strength of metal heat treatment

PURPOSE: Ni-Cr alloy does not contain Beryllium, causing the metal compound to form oxides in the furnace but by using Titanium as a chemical catalyst the forming of the oxides can be controlled, and by controlling the impurities formed on the metal surface, the possibility of the Ni-Cr alloy bond strength being increased can be analysed. MATERIALS AND METHODS: Titanium was used as a chemical catalyst in the porcelain for the oxidation of beryllium-free metal (Ni-Cr) alloy. The T1 group, which does not use Titanium power as a chemical catalyst is a reference model for comparison. The T2 group and T3 group used 10 g and 20 g of Titanium power, respectively. They are fabricated to observe the shear bond strength and surface properties. There was no significance when One-way ANOVA analysis/Tukey Honestly Significant Difference Test was conducted for statistical analysis among groups (P > 0.05). RESULTS: Results of measuring the three-point flexural bond strength of the Ni-Cr alloy and thickness of the oxide film. Experiment T3 using 20 g Titanium chemical catalyst: 39.22 ± 3.41 MPa and 6.66 µm, having the highest bond strength and thinness of oxide film. Experiment T2 using 10 g Titanium chemical catalyst: 34.65 ± 1.39 MPa and 13.22 µm. Experiment T1 using no Titanium chemical catalyst: 32.37 ± 1.91 MPa and 22.22 µm. CONCLUSION: The T2 and T3 experiments using Titanium chemical catalyst showed higher bond strength for the Ni-Cr alloy and lower thickness of oxide film than experiment T1, and the titanium catalyst being able to increase bond strength was observed.

Over-expression of Mycobacterium neoaurum 3-ketosteroid-∆ 1-dehydrogenase in Corynebacterium crenatum for efficient bioconversion of 4-androstene-3, 17-dione to androst-1, 4-diene-3, 17-dione

Background: 3-Ketosteroid-∆¹-dehydrogenase (KSDD), a flavoprotein enzyme, catalyzes the bioconversion of 4-androstene-3,17-dione (AD) to androst-1,4-diene-3,17-dione (ADD). To date, there has been no report about characterization of KSDD from Mycobacterium neoaurum strains, which were usually employed to produce AD or ADD by fermentation. Results: In this work, Corynebacterium crenatum was chosen asa new host for heterologous expression of KSDD from M. neoaurum JC-12 after codon optimization of the KSDD gene. SDS-PAGE and western blotting results indicated that the recombinant C. crenatum harboring the optimized ksdd (ksdd n) gene showed significantly improved ability to express KSDD. The expression level of KSDD was about 1.6-fold increased C. crenatum after codon optimization. After purification of the protein, we first characterized KSDD from M. neoaurum JC-12, and the results showed that the optimum temperature and pH for KSDD activity were 30°C and pH 7.0, respectively. The Km and Vmax values of purified KSDD were 8.91 µM and 6.43 mM/min. In this work, C. crenatum as a novel whole-cell catalyst was also employed and validated for bioconversion of AD to ADD. The highest transformation rate of AD to ADD by recombinant C. crenatum was about 83.87% after 10 h reaction time, which was more efficient than M. neoaurum JC-12 (only 3.56% at 10 h). Conclusions: In this work, basing on the codon optimization, overexpression, purification and characterization of KSDD, we constructed a novel system, the recombinant C. crenatum SYPA 5-5 expressing KSDD, to accumulate ADDfromADefficiently. This work provided new insights into strengthening sterol catabolism by overexpressing the key enzyme KSDD, for efficient ADD production.

Discovery of noveI EphB4 inhibitors based on pharmacophore modeIing and virtuaI screening techniques / 中国药科大学学报

The objective of this paper is to discover new potent inhibitors against EphB4 for cancer therapy via computer-aided drug design strategies including building 3D-QSAR models,virtual screening and molecular doc-king means.The first step is to generate pharmacophore models based on Catalyst/HypoGen algorithm.The best model,Hypo1,has the highest Correl value (0.96),the lowest RMS value (0.89),the closest total cost (101.26) to fixed cost (89.20),and the best Δcost (89.14).Subsequently,Hypo1 was subjected to test set validation and Fischer′s randomization verification and then was used as a 3D query to screen database.In order to further nar-row the number of hits,drug-likeness screening and molecular docking techniques were applied.Finally,23 novel molecules with diverse scaffolds were selected as possible candidates against EphB4 for further studies based on predicted activity analysis,docking scores,and binding modes analysis methods.