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1.
BMC Chem ; 18(1): 87, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38685077

RESUMO

2,6-Di-tert-butyl-4-methylphenol (BHT) is an excellent antioxidant that is easily oxidized to 2,6-di-tert-butyl-4-hydroperoxyl-4-methyl-2,5-cyclohexadienone (BHTOOH). For the safety of BHT production and usage, it is meaningful to study the thermal stability and decomposition properties of BHT and BHTOOH. In this paper, the thermal decomposition properties of BHT and BHTOOH were compared by the mini closed pressure vessel test (MCPVT) and differential scanning calorimetry (DSC). Their kinetics of thermal decomposition were studied using thermogravimetric analysis (TGA). The thermal decomposition products of BHT and BHTOOH were analyzed by gas chromatography-mass spectrometry (GC-MS). The results show that there was no significant change in temperature pressure when BHT was warmed up under a nitrogen atmosphere, indicating that BHT was stable within 400 K. The thermal decomposition reaction of BHTOOH was rapid with an initial reaction temperature of 375.2 K. The initial exothermic temperature (Ti) and heat release (QDSC) of DSC were 384.9 K and 865.0 J g-1, respectively. The apparent activation energies (Ea) for the thermal decomposition reactions of BHT and BHTOOH calculated by the Kissinger method were 151.8 kJ mol-1 and 66.07 kJ mol-1, respectively. The main decomposition products of BHT were isobutene and 2-tert-butyl-4-methylphenol. The thermal decomposition products of BHTOOH included BHT, 2,6-di-tert-butyl-4-ethylphenol, 3,5-di-tert-butyl-4-hydroxybenzaldehyde, 4,4'-(1,2-ethanediyl) bis [2,6-bis (1,1-dimethylethyl) phenol, etc. Based on the thermal decomposition behavior and products, the reaction pathway has been described. These results indicate that BHT is a potential thermal hazard during production, storage and application. For the safety of the chemical industry, the oxidation of BHT should be avoided.

2.
Braz J Microbiol ; 55(1): 777-788, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38147271

RESUMO

Organic agriculture is a farming method that provides healthy food and is friendly to the environment, and it is developing rapidly worldwide. This study compared microbial communities in organic farming (Or) paddy fields to those in nonorganic farming (Nr) paddy fields based on 16S rDNA sequencing and analysis. The predominant microorganisms in both soils were Proteobacteria, Chloroflexi, Acidobacteria, Actinobacteria, and Nitrospirota. The alpha diversity of the paddy soil microbial communities was not different between the nonorganic and organic farming systems. The beta diversity of nonmetric multidimensional scaling (NMDS) revealed that the two groups were significantly separated. Distance-based redundancy analysis (db-RDA) suggested that soil pH and electrical conductivity (EC) had a positive relationship with the microbes in organic paddy soils. There were 23 amplicon sequence variants (ASVs) that showed differential abundance. Among them, g_B1-7BS (Proteobacteria), s_Sulfuricaulis limicola (Proteobacteria), g_GAL15 (p_GAL15), c_Thermodesulfovibrionia (Nitrospirota), two of f_Anaerolineaceae (Chloroflexi), and two of g_S085 (Chloroflexi) showed that they were more abundant in organic soils, whereas g_11-24 (Acidobacteriota), g__Subgroup_7 (Acidobacteriota), and g_Bacillus (Firmicutes) showed differential abundance in nonorganic paddy soils. Functional prediction of microbial communities in paddy soils showed that functions related to carbohydrate metabolism could be the major metabolic activities. Our work indicates that organic farming differs from nonorganic farming in terms of microbial composition in paddy soils and provides specific microbes that might be helpful for understanding soil fertility.


Assuntos
Actinobacteria , Microbiota , Oryza , Solo/química , Microbiologia do Solo , RNA Ribossômico 16S/genética , Agricultura/métodos , Bactérias/genética , Actinobacteria/genética , Oryza/genética
3.
ACS Omega ; 8(43): 40206-40211, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37929151

RESUMO

The synthesis of one-dimensional zinc oxide nanorod photoelectrodes through a chemical solution method and their application in dye-sensitized solar cells are described in this paper. A multiple growth approach was used to fabricate zinc oxide nanorods with varying length-to-diameter ratios, and their dye adsorption properties were characterized using ultraviolet-visible spectroscopy. The zinc oxide photoelectrodes with different length-to-diameter ratios were subsequently incorporated into dye-sensitized solar cells, and their performance and carrier lifetime were analyzed using a solar simulator, monochromatic incident photon-to-electron conversion efficiency, and electrochemical impedance spectroscopy. The highest efficiency achieved was 0.74%. The results indicate that the quality of the zinc oxide nanorods synthesized through the multiple growth approach is consistent, with the uniformity and morphology of the nanorods having the greatest impact on device efficiency.

4.
Ultrasound Q ; 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37918115

RESUMO

ABSTRACT: The right ventricular fetal tricuspid annular plane systolic excursion index (FTI) can be used to evaluate right ventricular systolic function. The purpose of this study was to establish the reference range of the FTI in normal fetuses and evaluate its diagnostic value in hypertensive disorders during pregnancy. In this prospective observational study, the right ventricular FTI was measured in 208 normal single-gestation fetuses between 20 and 40 weeks. With the increase in gestational age, the right ventricular FTI did not significantly fluctuate. With the increase in the severity of HDCP, the right ventricular FTI decreased gradually. Compared with the normal group, the low right ventricular FTI group had a higher incidence of premature delivery and emergency delivery due to continuous abnormal fetal heart monitoring, but there were no significant differences in low birth weight, new born Apgar score less than 7 in 5 minutes, or admission to the neonatal intensive care unit. The FTI of the right ventricle of normal fetuses is relatively constant at different gestational weeks. The right ventricular FTI can be used to evaluate fetal cardiac function changes in pregnant women with HDCP.

5.
BMC Chem ; 17(1): 110, 2023 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-37660031

RESUMO

In this study, the oxidation characteristics of isoprene were investigated using a custom-designed mini closed pressure vessel test (MCPVT). The results show that isoprene is unstable and polymerization occurs under a nitrogen atmosphere. Under an oxygen atmosphere, the oxidation process of isoprene was divided into three stages: (1) isoprene reacts with oxygen to produce peroxide; (2) Peroxides produce free radicals through thermal decomposition; (3) Free radicals cause complex oxidation and thermal runaway reactions. The oxidation of isoprene conforms to the second-order reaction kinetics, and the activation energy was 86.88 kJ·mol-1. The thermal decomposition characteristics of the total oxidation product and purified peroxide mixture were determined by differential scanning calorimetry (DSC). The initial exothermic temperatures Ton were 371.17 K and 365.84 K, respectively. And the decomposition heat QDSC were 816.66 J·g-1 and 991.08 J·g-1, respectively. It indicates that high concentration of isoprene peroxide has a high risk of thermal runaway. The results of thermal runaway experiment showed that the temperature and pressure of isoprene oxidation were prone to rise rapidly, which indicates that the oxidation reaction was dangerous. The reaction products of isoprene were analyzed by gas chromatography-mass spectrometry (GC-MS). The main oxidation products were methyl vinyl ketone, methacrolein, 3-methylfuran, etc. The main thermal runaway products were dimethoxymethane, 2,3-pentanedione, naphthalene, etc. Based on the reaction products, the possible reaction pathway of isoprene was proposed.

6.
Nanomaterials (Basel) ; 13(3)2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36770393

RESUMO

In Cu2ZnSnS4 (CZTS) solar cells, it is crucial to suppress the generation of and remove the SnS2 secondary phase to improve the solar cell characteristics, as the SnS2 secondary phase affects the barrier for carrier collection and diode characteristics of the device. In this study, the nano-metallic precursor was modified to effectively suppress the generation of the SnS2 secondary phase on the surface and simultaneously improve the uniformity and quality of the thin film. The CZTS bifacial solar cells prepared via the proposed method exhibited significantly improved junction-rectifying characteristics, as the efficiency was improved to 1.59%. The proposed method to figurremove SnS2 is effective, simple, and environmentally friendly.

7.
Pilot Feasibility Stud ; 9(1): 8, 2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36639647

RESUMO

BACKGROUND: At present, even the first-line medication epinephrine still shows no evidence of a favourable neurological outcome in patients with sudden cardiac arrest (SCA). The high mortality of patients with postcardiac arrest syndrome (PCAS) can be attributed to brain injury, myocardial dysfunction, systemic ischaemia/reperfusion response, and persistent precipitating pathology. Targeted temperature management, the only clinically proven method in the treatment of PCAS, is still associated with a series of problems that have not been completely resolved. Acupuncture is a crucial therapy in traditional Chinese medicine. On the basis of the results of previous studies, we hypothesize that electroacupuncture (EA) might provide therapeutic benefits in the treatment of PCAS. This study will explore the feasibility of EA on SCA patients. METHODS: This is a prospective pilot, randomized controlled clinical trial. Eligible patients with PCAS after in-hospital cardiac arrest (IHCA) admitted to our department will be randomly allocated to the control group or the EA group. Both groups will receive standard therapy according to American Heart Association guidelines for cardiopulmonary resuscitation. However, the EA group will also receive acupuncture at the Baihui acupoint (GV20) and Zusanli acupoint (ST36) with EA stimulation for 30 min using a dense-dispersed wave at frequencies of 20 and 100 Hz, a current intensity of less than 10 mA, and a pulse width of 0.5 ms. EA treatment will be administered for up to 14 days (until either discharge or death). The primary endpoint is survival with a favourable neurological outcome. The secondary endpoints are neurological scores, cardiac function parameters, and other clinical parameters, including Sequential Organ Failure Assessment (SOFA) scores and Acute Physiology and Chronic Health Evaluation (APACHE) II scores, on days 0 to 28. DISCUSSION: This study will provide crucial clinical evidence on the efficacy of EA in PCAS when used as an adjunctive treatment with AHA standard therapy. TRIAL REGISTRATION: chictr.org.cn : ChiCTR2000040040. Registered on 19 November 2020. Retrospectively registered. http://www.chictr.org.cn/ .

8.
Materials (Basel) ; 15(22)2022 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-36431582

RESUMO

Copper(II)-containing aluminum phosphate material (CuAPO-5) was synthesized hydrothermally and used as a multiphase catalyst for the oxidation of α-pinene to verbenone. The catalysts were analyzed using X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area techniques, X-ray photoelectron spectroscopy (XPS), and ammonia temperature programmed reduction (NH3-TPD). Scanning electron microscopy (SEM), X-ray energy spectrometry (EDS), inductively coupled plasma emission spectroscopy (ICP-OES), Fourier infrared spectroscopy (FT-IR), and ultraviolet-visible spectroscopy (UV-vis) were performed to characterize the material. The effects of reaction temperature, reaction time, n(α-pinene)/n(TBHP), and solvent on the catalytic performance of CuAPO-5 were investigated. The results show that all the prepared catalysts have AFI topology and a large specific surface area. Copper is evenly distributed in the skeleton in a bivalent form. The introduction of copper increases the acid content of the catalyst. Under the optimized reaction conditions, 96.8% conversion of α-pinene and 46.4% selectivity to verbenone were achieved by CuAPO-5(0.06) molecular sieve within a reaction time of 12 h. CuAPO-5(0.06) can be recycled for five cycles without losing the conversion of α-pinene and the selectivity to verbenone.

9.
Animals (Basel) ; 12(21)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36359091

RESUMO

According to pigeon racing rules in Taiwan, the pigeon raiser must decide which juveniles will be chosen as soon as possible. Differentiating the sex of young pigeons based on appearances, and other traditional methods, can be time-consuming and require several pieces of equipment. Recombinase polymerase amplification (RPA) combined with a lateral-flow dipstick (LFD) could further simplify the presentation of amplification results. A designed reverse primer and probe were labeled with biotin and FAM (fluorescein), respectively, to serve as ligands in the LFD. With the addition of a designed forward primer, the RPA-LFD can be used to perform sex identification of pigeon DNA. The optimal conditions were determined to require at least 6.3 pg of the DNA template, a temperature of 37 °C, and a reaction time of at least 20 min. Under these conditions, the test band area on the strip appeared as a dark color if the sample contained female template DNA, whereas the male DNA samples did not produce any test signal in any of the conditions. The results of random samples using RPA-LFD under the optimal conditions agreed with the results of the same samples determined by PCR-agarose gel electrophoresis. The approach in this study represents a rapid and accurate method for pigeon sexing.

10.
Anim Biotechnol ; : 1-12, 2022 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-36309814

RESUMO

Due to the poor growth rate of the Taiwan black (TB) goat in Taiwan, many exotic breeds were brought into breeding schemes to improve TB goat. However, the excessive cross-breeding of alien species with TB goat has decreased its population numbers, genetic variation and biodiversity. Therefore, TB goat population considered an endemic species in Taiwan that needed to be conservation. The objective of the present study was to analyze the genetic structure and TB goat using genetic markers for genetic improvement and to sustain germplasm conservation and utilization. 15 microsatellite markers, divided into three sets, were used to analyze 690 goats sampled from 10 goat populations. The average number of alleles (Na) and effective alleles (Ne) was 11.87 ± 3.93 and 5.093 ± 1.768, respectively. The average expected heterozygosity (HE) and observed heterozygosity (HO) was 0.780 ± 0.084 and 0.602 ± 0.116, respectively. The average polymorphic information content (PIC) was 0.747 ± 0.103; FIS was 0.058 ± 0.075. All 15 microsatellite markers were highly polymorphic. The genetic distances between individuals were estimated to construct a phylogenetic tree. In present study, the 690 goat samples were divided into 8 clusters. The results indicated that these 15 microsatellite markers successfully clustered goat populations in Taiwan and could assist in the preservation of TB goats.

11.
R Soc Open Sci ; 9(9): 211479, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36117871

RESUMO

It has been a challenge to synthesize macrolide musk in excellent yields with high purity. KF-La/γ-Al2O3 catalyst was prepared from a highly basic mesoporous framework using a mild method. The prepared KF-La/γ-Al2O3 catalyst was employed for the synthesis of cyclopentadecanolide from methyl 15-hydroxypentadecanoate. The morphology and structure of prepared catalysts were characterized using XRD, TG-DTG, SEM, EDX, TEM, BET and CO2-TPD. The results revealed that the K3AlF6 and LaOF are produced on the surface of KF-La/γ-Al2O3, and LaO can promote the dispersion of KF on the surface of Al2O3. Catalysts pore size main distribution ranges between 10 and 30 nm, the maximum CO2 desorption temperature is 715°C when the La loading is 25%. Because F- ion has a higher electronegativity than O2- ion, the KF-promoted metal oxide (Al2O3 or/and La2O3) contained more strong basic sites, compared with that of the corresponding metal oxide. The yield of cyclopentadecanolide obtained at 0.5 g KF-25La/γ-Al2O3 catalyst and a reaction temperature of 190°C for 7 h were 58.50%, and the content after reactive distillation is 98.8%. The KF-La/γ-Al2O3 catalyst has a larger pore size and basic strength, which is more conducive to the macrolactonization of long-chain hydroxy ester.

12.
BMC Med Educ ; 22(1): 420, 2022 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-35655205

RESUMO

BACKGROUND: In the intensive care unit (ICU), internal jugular vein puncture and catheterization are basic rescue operations that physicians need to complete quickly and independently. It is necessary to improve the first-attempt success rate of internal jugular vein catheterization, shorten the catheterization duration and reduce the incidence of complications for standardized training residents (STRs). OBJECTIVE: To improve first-attempt insertion success rates of internal jugular vein catheterization for STRs. METHODS: Based on the PDCA cycle management method and current situation investigation, the PDCA management objectives were set, and the implementation content, monitoring items and continuous improvement plan were formulated. The data of residents who were trained in the ICU of Fangcun Hospital, Second Affiliated Hospital of Guangzhou University of Chinese Medicine, from January 2016 to April 2016 and managed by the PDCA cycle (PDCA group), were compared with the data of residents trained in the same department from August 2015 to November 2015 before the implementation of PDCA (historic control group), the first-attempt success rate of puncture and catheterization, the duration of puncture and catheterization, and the incidence of complications were analysed. RESULTS: Thirty-six cases of internal jugular vein catheterization were performed by the PDCA group, 21 cases (58%) were performed by residents in the third year of standardized training, and 15 cases (42%) were performed by residents in the second year of standardized training. Compared with the historic control group, there was no significant difference in the seniority of residents (X2 = 0.240, P = 0.625) or the 'majors of the residents (X2 = 1.306, P = 0.835). The first-attempt success rate of puncture in the PDCA group was 94% (34/36), which was significantly higher than that of the historic control group (55% (11/20) (P = 0.001). In the PDCA group, the first-attempt success rate of puncture among third-year standardized training residents was 95% (20/21), and the first-attempt success rate in the second-year was 93% (14/15), which were significantly higher than the corresponding rates of 62% (8/13) and 43% (3/7) respectively, in the historic control group (all P = 0.021). The duration of catheterization was [4 (3,5)] min after PDCA, which was significantly shorter than that in the historic control group [9 (6.25,13.00)] min (Z = - 5.214, P < 0.001). The incidence rate of complications in the PDCA group was 0% (0 /36), which was significantly lower than the rate of 20% (4 / 20) in the historic control group (P < 0.013). CONCLUSION: PDCA cycle management can help improve the first-attempt success rate of internal jugular vein puncture and catheterization, shorten the duration of puncture and catheterization, and reduce the incidence of complications. The idea and method of PDCA cycle management can be applied to other training and management protocols for STRs.


Assuntos
Cateterismo Venoso Central , Veias Jugulares , Cateterismo Venoso Central/efeitos adversos , Humanos , Incidência , Unidades de Terapia Intensiva
13.
Complement Ther Med ; 69: 102846, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35688327

RESUMO

BACKGROUND: There are many studies that have interrogated the evolution and use of electroacupuncture (EA). We aimed to evaluate the research status, cooperation and development of EA in the past 10 years. METHODS: We obtained data on the EA from the Web of Science core collection database. CiteSpace 5.7. R1 software was used to assess research cooperation through analysis of authors, institutions and countries. In addition, keyword cluster analysis, references and burst detection were analyzed to explore research hotspots and trends in the field of EA. RESULTS: We included a total of 3019 citing literature and 78,235 cited literature for analysis. The data showed that there has been a rise in the global number of EA studies in the past decade. Besides, the data demonstrated that China has made outstanding contribution in the development of EA. Whereas there is inter-agency cooperation in China, there is less cooperation with other countries. In addition, we showed frequent use of keywords such as "expression", "stimulation", or "pain". Besides, neuroscience was the main research area, followed by general medicine and oncology. Furthermore, with the improved research methods and technologies, there is enhanced overall quality of the studies. CONCLUSION: Taken together, our findings demonstrate a steady increase in the studies involving EA. However, the studies are unevenly distributed among countries and thus there is need for closer international cooperation.


Assuntos
Eletroacupuntura , Bibliometria , China , Humanos , Publicações , Software
14.
Anim Biosci ; 35(9): 1314-1326, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35240021

RESUMO

OBJECTIVE: Alongside the rise of animal-protection awareness in Taiwan, the public has been paying more attention to dog genetic deficiencies due to inbreeding in the pet market. The goal of this study was to isolate novel microsatellite markers for monitoring the genetic structure of domestic dog populations in Taiwan. METHODS: A total of 113 DNA samples from three dog breeds-beagles (BEs), bichons (BIs), and schnauzers (SCs)-were used in subsequent polymorphic tests applying the 14 novel microsatellite markers that were isolated in this study. RESULTS: The results showed that the high level of genetic diversity observed in these novel microsatellite markers provided strong discriminatory power. The estimated probability of identity (P(ID)) and the probability of identity among sibs (P(ID)sib) for the 14 novel microsatellite markers were 1.7×10-12 and 1.6×10-5, respectively. Furthermore, the power of exclusion for the 14 novel microsatellite markers was 99.98%. The neighbor-joining trees constructed among the three breeds indicated that the 14 sets of novel microsatellite markers were sufficient to correctly cluster the BEs, BIs, and SCs. The principal coordinate analysis plot showed that the dogs could be accurately separated by these 14 loci based on different breeds; moreover, the Beagles from different sources were also distinguished. The first, the second, and the third principal coordinates could be used to explain 44.15%, 26.35%, and 19.97% of the genetic variation. CONCLUSION: The results of this study could enable powerful monitoring of the genetic structure of domestic dog populations in Taiwan.

15.
BMC Chem ; 16(1): 4, 2022 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-35180888

RESUMO

The reaction process of gaseous 1,3-butadiene following ultraviolet irradiation at the temperature range from 298 to 323 K under nitrogen atmosphere was monitored by UV-vis spectrophotometry. A gaseous mini-reactor was used as a reaction vessel and could be directly monitored in a UV-vis spectrophotometer. We investigated the reactivity and kinetics of 1,3-butadiene under non-UV and UV irradiation to evaluate its photochemical stability. A second-order kinetic model with 50.48 kJ·mol-1 activation energy fitted the reaction data for non-UV irradiation, whereas a first-order kinetic model was appropriate in the case of UV irradiation with activation energies of 19.92-43.65 kJ mol-1. This indicates that ultraviolet light could accelerate the photolysis reaction rate of 1,3-butadiene. In addition, the reaction products were determined using gas chromatography-mass spectrometry (GC-MS), and the reaction pathways were identified. The photolysis of 1,3-butadiene gave rise to various volatile products by cleavage and rearrangement of single C-C bonds. The differences between dimerization and dissociation of 1,3-butadiene under ultraviolet irradiation were elucidated by combining experimental and theoretical methods. The present findings provide fundamental insight into the photochemistry of 1,3-butadiene compounds.

16.
Altern Ther Health Med ; 28(6): 156-160, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33128536

RESUMO

A 42-year-old male was hospitalized 13.5 hours after ingestion of 50 mg (approximately 0.7 mg/kg) colchicine in a suicide attempt. The patient developed gastrointestinal dysfunction, grade IV myelosuppression, and restrictive respiratory failure without occurrences of cardiovascular collapse or fatal dysrhythmias. Emergency treatment with integrated Chinese and Western medicine was started and the patient fully recovered without long-term complications. This report describes a massive overdose of colchicine successfully treated with integrated Chinese and Western medicine. Current treatment options are reviewed.


Assuntos
Overdose de Drogas , Gastroenteropatias , Adulto , China , Colchicina , Overdose de Drogas/tratamento farmacológico , Humanos , Masculino , Tentativa de Suicídio
17.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 2786-2789, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34891827

RESUMO

Ocular surface disorder is one of common and prevalence eye diseases and complex to be recognized accurately. This work presents automatic classification of ocular surface disorders in accordance with densely connected convolutional networks and smartphone imaging. We use various smartphone cameras to collect clinical images that contain normal and abnormal, and modify end-to-end densely connected convolutional networks that use a hybrid unit to learn more diverse features, significantly reducing the network depth, the total number of parameters and the float calculation. The validation results demonstrate that our proposed method provides a promising and effective strategy to accurately screen ocular surface disorders. In particular, our deeply learned smartphone photographs based classification method achieved an average automatic recognition accuracy of 90.6%, while it is conveniently used by patients and integrated into smartphone applications for automatic patient-self screening ocular surface diseases without seeing a doctor in person in a hospital.


Assuntos
Oftalmopatias , Aplicativos Móveis , Oftalmopatias/diagnóstico por imagem , Humanos , Redes Neurais de Computação , Smartphone
18.
Front Chem ; 9: 770247, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34957045

RESUMO

The synthesis costs of macrolide musks are higher than those of other commercial musks. To make this process less expensive, eggshell waste was calcined at a low temperature to obtain a catalyst for the cyclopentadecanolide production via reactive distillation using a glycerol entrainer. X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy analyses of the original and recovered catalysts revealed that the main catalytic ingredient was calcium glycerolate (CaG) and not calcium diglyceroxide (CaDG). The basic strengths of CaG and CaDG obtained by Hammett indicators were 7.2 < H_≤ 15.0 and 9.8 < H_≤15.0, while the corresponding base amounts were 1.9 and 7.3 mmol/ g, respectively. Because CaG was soluble in glycerine, the catalyst was efficiently reused. The reaction product containing over 95.0% cyclopentadecanolide with a yield of 49.8% was obtained at a temperature of 190°C and catalyst amount of 12 wt% after 7 h of reaction. Thus, eggshell waste may be directly placed into the reaction mixture after calcination at 600°C to synthesise a large amount of cyclopentadecanolide within a relatively short time. The results of this work indicate that eggshell waste can serve as a potential eco-friendly and affordable catalyst source for the production of macrolide musks.

19.
Materials (Basel) ; 14(21)2021 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-34771839

RESUMO

In this study, a radio-frequency magnetron sputter system was used to deposit Al2O3 doped ZnO (AZO) thin films at room temperature, and the soda lime glass (SLG) substrates were placed at different zones relative to the center of the sample holder under the target. The samples were then analyzed using an X-ray diffractometer, Hall-effect measurement system, UV-visible spectrophotometer, and X-ray photoelectron spectroscopy. It was found that the electrical, structural, and optical properties of AZO films strongly depend on the target racetrack. The AZO thin film grown at a location outside the racetrack not only has the most suitable figure of merit for transparent conductive films, but also retains the least residual stress, which makes it the most suitable candidate for use as a CZTSe transparent conductive layer. When applied to CZTSe solar cells, the photoelectric efficiency is 3.56%.

20.
Antimicrob Agents Chemother ; 65(12): e0047021, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34491808

RESUMO

Eliminating the latent HIV reservoir remains a difficult problem for creating an HIV functional cure or achieving remission. The "block-and-lock" strategy aims to steadily suppress transcription of the viral reservoir and lock the HIV promoter in deep latency using latency-promoting agents (LPAs). However, to date, most of the investigated LPA candidates are not available for clinical trials, and some of them exhibit immune-related adverse reactions. The discovery and development of new, active, and safe LPA candidates for an HIV cure are necessary to eliminate residual HIV-1 viremia through the block-and-lock strategy. In this study, we demonstrated that a new small-molecule compound, Q308, silenced the HIV-1 provirus by inhibiting Tat-mediated gene transcription and selectively downregulating the expression levels of the facilitated chromatin transcription (FACT) complex. Strikingly, Q308 induced the preferential apoptosis in HIV-1 latently infected cells, indicating that Q308 may reduce the size of the viral reservoir and thus further prevent viral rebound. These findings highlight that Q308 is a novel and safe anti-HIV-1 inhibitor candidate for a functional cure.


Assuntos
Infecções por HIV , HIV-1 , Linfócitos T CD4-Positivos , Cromatina , Infecções por HIV/tratamento farmacológico , HIV-1/genética , Humanos , Provírus/genética , Latência Viral
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