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1.
Zhongguo Zhong Yao Za Zhi ; 44(19): 4121-4124, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31872687

RESUMO

Due to the large amount of Codonopsis pilosula planted in Weiyuan county,and the arable land area,the local medicinal materials office uses a large amount of manpower,financial resources and material resources to estimate its area every year. In order to extract the information of local Chinese medicinal materials more quickly and simply,we try to apply remote sensing technology to the extraction of Chinese medicinal materials. This paper will use Weiyuan county of Gansu province as the research area,and use the domestic ZY-3 Satellite multi-spectral remote sensing image as the data source to find out the spectral characteristics of the party's participation in other remote sensing images. The visual interpretation method was used to extract the planting area of the C. pilosula in Weiyuan county. The estimated value of the planting area of C. pilosula using satellite remote sensing technology was 75 965 mu( 1 mu≈667 m2),which was basically consistent with the field survey data of the local medicinal materials office. After the accuracy verification,it was found that the precision of C. pilosula planted by visual interpretation was more than 70%. It is concluded that the satellite remote sensing technology can be used to extract the information of C. pilosula and it can provide the relevant information of the planting area of Chinese medicinal materials quickly and accurately.


Assuntos
Codonopsis , Plantas Medicinais , Tecnologia de Sensoriamento Remoto , China
2.
Zhongguo Zhong Yao Za Zhi ; 44(19): 4125-4128, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31872688

RESUMO

Due to the large amount of nutrients required during the cultivation of Angelica sinensis and in order to prevent the occurrence of pests and diseases,and the annual reduction of the planting area of Angelica and the balance of supply and demand of A. sinensis,the A. sinensis plantation adopts the rotation mode. This paper takes Wuyuan county of Gansu province as the research scope and use GF-1 Satellite data as the data source,using remote sensing technology combined with field survey results,to explore the effective method of visual interpretation for the extraction of A. sinensis planting area. A sample was selected to generate a spectrum according to different feature types. The different characteristics of A. sinensis and other features were analyzed and distinguished in remote sensing images,so that the A. sinensis planting plots were extracted and verified in remote sensing images. The results showed that the accuracy verification value of the visual interpretation method was 95. 85%. It is determined that the visual interpretation method can effectively extract the A. sinensis planting plots within the research scope and realize the comprehensive grasp of the spatial distribution information of A. sinensis.


Assuntos
Angelica sinensis , Plantas Medicinais , Tecnologia de Sensoriamento Remoto , China
3.
Small ; 15(22): e1900426, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30977961

RESUMO

Metal-organic frameworks (MOFs) can be fine-tuned to boost sorbent-sorbate interactions in order to improve gas sorption and separation performance, but the design of MOFs with ideal structural features for gas separation applications remains a challenge. Herein it is reported that unsaturated alkali metal sites can be immobilized in MOFs through a tetrazole based motif and that gas affinity can thereby be boosted. In the prototypal MOF of this type-NKU-521 (NKU denotes Nankai University), K+ cations are effectively embedded in a trinuclear Co2+ -tetrazole coordination motif. The embedded K+ sites are exposed to the pores of NKU-521 through water removal, and the isosteric heat (Qst ) for CO2 is boosted to 41 kJ mol-1 . The nature of the binding site is validated by molecular simulations and structural characterization. The K+ cations in effect serve as gas traps and boost the CO2 -framework affinity, as measured by the Qst , by 24%. In addition, the impact of unsaturated alkali metal sites upon the separation of hydrocarbons is evaluated for the first time in MOFs using ideal adsorbed solution theory (IAST) calculations and column breakthrough experiments. The results reveal that the presence of exposed K+ sites benefits gas sorption and hydrocarbon separation performances of this MOF.

4.
Chem Biol Interact ; 304: 97-105, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30878453

RESUMO

PURPOSE: Glucocorticoid-induced osteonecrosis of the femoral head (GIONFH) is a common disease following long-term use or large doses of glucocorticoids. The pathogenesis of GIONFH remains controversial, and abnormal bone metabolism caused by glucocorticoids(GCs) may be one of the important factors. Due to its positive effect on bone remodeling, naringin shows potential therapeutic effects in bone metabolism-related diseases. In this study, we hypothesized that naringin regulated bone metabolism in rat GIONFH via the Akt/Bad signal cascades. METHODS: In vitro, a dexamethasone (Dex)- or naringin-treated cell model was used to evaluate the function of naringin. In vivo, methylprednisolone (MPS)-treated rat model was used to evaluate the function of naringin in GIONFH. In vitro, Cell Counting Kit-8 (CCK-8) and Edu staining was used to evaluate the proliferation of osteocytes, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, Annexin V-FITC-PI, and western blotting were used to evaluate the apoptosis of osteocytes. We also verified the effects of naringin on osteogenesis and osteoclastogenesis. In vivo, we used micro-CT (computed tomography), histological, and immunohistochemical analysis to evaluate the effect of naringin. Moreover, the mechanism of naringin regulating the bone metabolism through the Akt/Bad pathway was also investigated using bioinformatics analysis and western blotting. RESULTS: The results of in vitro study showed that Akt activated by naringin promoted osteogenesis and osteocyte proliferation; in addition, osteocyte apoptosis and osteoclastogenesis was inhibited by Akt activation and Bad suppression. According to the in vivo study, naringin prevented GIONFH in a rat model as shown by micro-CT scanning and histological and immunohistochemical analysis. CONCLUSIONS: Therefore, we concluded that naringin is an effective compound for promoting bone repair and preventing bone loss in rats with GIONFH through Akt/Bad signal cascades.


Assuntos
Cabeça do Fêmur/efeitos dos fármacos , Flavanonas/farmacologia , Glucocorticoides/farmacologia , Osteogênese/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Células 3T3 , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Cabeça do Fêmur/metabolismo , Camundongos , Estrutura Molecular , Proteínas Proto-Oncogênicas c-akt/metabolismo , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade
5.
Inorg Chem ; 57(8): 4620-4628, 2018 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-29608062

RESUMO

Metal-organic frameworks (MOFs) with diverse structures, adjustable pore sizes, and high surface areas have exhibited awesome potential in many fields. Here we report a simple carbonization strategy to obtain a series of core-shell structured Co/Co3O4 nanoparticles encapsulated into nitrogen-doped carbon shells from cobalt-based metal-organic framework precursors at different carbonization temperatures. When it is applied as an anodes for lithium ion batteries, the Co/Co3O4@N-C-700 electrode delivers a maximum initial discharge capacity of 1535 mAh g-1, the highest reversible capacity (903 mAh g-1 at a current density of 100 mA g-1 after 100 cycles), and the best rate performance (i.e., 774 mAh g-1 at a current density of 1.0 A g-1 after 100 cycles) in comparison with those of Co/Co3O4@N-C-600 and Co/Co3O4@N-C-800 electrodes. The excellent electrochemical performance could be mainly attributed to the unique core-shell structure, abundant graphited carbon, and the well-dispersed Co/Co3O4 nanoparticles which can promote the specific capacity through conversion reactions.

6.
Sci Rep ; 7(1): 13345, 2017 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-29042586

RESUMO

The mechanism behind osteonecrosis of the femoral head (ONFH) remains unclear. The aim of this study was to explore the pathogenesis of ONFH from a biomechanical standpoint to provide a theoretical basis for improved treatments. We compared the bone structure of fractured femoral heads with that of necrotic femoral heads by Micro-CT scanning and histological evaluation. In addition, we compared the biomechanical properties of each zone in fractured femoral heads with those in necrotic femoral heads by using biomechanical tests. Compared with fractured femoral heads, bone microarchitecture and bone morphometry in necrotic zone and sclerotic zone of necrotic femoral heads have altered markedly. In addition, the biomechanical properties of the necrotic zone in femoral heads weaken markedly, while those of the sclerotic zone strengthen. We hypothesize that discordance between bone structure and function of the femoral head may be involved in the pathogenesis of ONFH and that more attention should be paid to the prevention and treatment of such discordance.


Assuntos
Fenômenos Biomecânicos , Necrose da Cabeça do Fêmur/patologia , Cabeça do Fêmur/patologia , Idoso , Densidade Óssea , Feminino , Cabeça do Fêmur/diagnóstico por imagem , Necrose da Cabeça do Fêmur/diagnóstico por imagem , Humanos , Imagem Tridimensional , Masculino , Pessoa de Meia-Idade , Microtomografia por Raio-X
7.
Int J Surg ; 46: 53-60, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28823794

RESUMO

OBJECTIVE: A meta analysis to compare efficacy and safety of bicompartmental knee arthroplasty (BKA) and Total knee arthroplasty (TKA) in patients with bicompartmental knee osteoarthritis (OA). METHOD: Electronic databases included PubMed, Embase, web of science and the Cochrane Library up to the end of July 2017 were searched. High quality randomized controlled trials(RCTs) and prospective clinical controlled trials were selected based on inclusion criteria. RevMan 5.3 were used for the meta-analysis. RESULTS: Five studies containing 261 patients meet the inclusion criteria. Knee Society score (KSS)-Knee Score,KSS-Function Score, and flexion range of the knee in BKA group is greater than those in TKA group (P = 0.03,P < 0.0001,P = 0.0008 respectively); Hip-Knee-Ankle (HKA) angle in BKA group is smaller than TKA group (P < 0.00001); more postoperative complications are observed in BKA group (P = 0.007); no significant difference was found in proportion of revision between the two groups (p = 0.11). CONCLUSION: Compared to TKA, BKA can bring better knee function and life quality to patients with bicompartmental knee OA. Though BKA may cause more postoperative complications, it can be an alternative treatment of TKA for patients with bicompartmental knee OA.


Assuntos
Artroplastia do Joelho/métodos , Osteoartrite do Joelho/cirurgia , Idoso , Artroplastia do Joelho/efeitos adversos , Feminino , Humanos , Articulação do Joelho/fisiopatologia , Articulação do Joelho/cirurgia , Masculino , Pessoa de Meia-Idade , Osteoartrite do Joelho/fisiopatologia , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto , Amplitude de Movimento Articular , Resultado do Tratamento
8.
J Arthroplasty ; 32(10): 3238-3248.e3, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28606458

RESUMO

BACKGROUND: Total knee arthroplasty (TKA) is associated with intense postoperative pain with a need for early ambulation to gain function and prevent postoperative complications. Compared with femoral nerve block (FNB), adductor canal block (ACB) can relieve postoperative pain and preserve quadriceps muscle strength. This meta-analysis was conducted to investigate which analgesic method provides better pain relief and functional recovery after TKA. METHOD: We conducted a meta-analysis to identify relevant randomized controlled trials involving ACB and FNB after TKA in electronic databases, including Web of Science, Embase, PubMed, and the Cochrane Library, up to November 2016. Finally, 9 randomized controlled trials involving 609 patients (668 knees) were included in our study. Review Manager Software and Grading of Recommendations Assessment, Development, and Evaluation profiler were used to perform the meta-analysis. RESULTS: Compared with FNB, ACB resulted in better quadriceps muscle strength and mobilization ability. There were no significant differences in the visual analog scale at rest, visual analog scale with mobilization, rescue opioid consumption, patient satisfaction, and length of hospital stay. CONCLUSION: Compared with FNB, ACB shows similar pain control after TKA. However, ACB can better preserve quadriceps muscle strength and improve mobilization ability. In conclusion, ACB showed better functional recovery after TKA without compromising pain control. Therefore, ACB is recommended as an alternative analgesic method for early ambulation after TKA.


Assuntos
Artroplastia do Joelho , Nervo Femoral , Bloqueio Nervoso/métodos , Manejo da Dor/métodos , Dor Pós-Operatória/prevenção & controle , Analgésicos Opioides/administração & dosagem , Anestesia por Condução , Deambulação Precoce , Humanos , Tempo de Internação , Força Muscular , Músculo Esquelético , Medição da Dor , Satisfação do Paciente , Complicações Pós-Operatórias , Músculo Quadríceps/fisiologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Recuperação de Função Fisiológica , Coxa da Perna , Escala Visual Analógica
9.
Nat Commun ; 8: 14841, 2017 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-28332576

RESUMO

Although great success has been achieved in asymmetric fluoroalkylation reactions via nucleophilic or electrophilic processes, the development of asymmetric radical versions of this type of reactions remains a formidable challenge because of the involvement of highly reactive radical species. Here we report a catalytic asymmetric radical aminoperfluoroalkylation and aminodifluoromethylation of alkenes with commercially available fluoroalkylsulfonyl chlorides as the radical sources, providing a versatile platform to access four types of enantioenriched α-tertiary pyrrolidines bearing ß-perfluorobutanyl, trifluoromethyl, difluoroacetyl and even difluoromethyl groups in excellent yields and with excellent enantioselectivity. The key to success is not only the introduction of the CuBr/chiral phosphoric acid dual-catalytic system but also the use of silver carbonate to suppress strong background and side hydroamination reactions caused by a stoichiometric amount of the in situ generated HCl. Broad substrate scope, excellent functional group tolerance and versatile functionalization of the products make this approach very practical and attractive.

10.
Int J Surg ; 39: 95-103, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28137554

RESUMO

OBJECTIVE: A meta analysis to compare efficacy and safety of intraarticular hyaluronic acid (HA) and intraarticular corticosteroids (CS) in patients with knee osteoarthritis. METHOD: Potential studies were searched from the electronic databases included PubMed, Embase, web of science and the Cochrane Library up to August 2016. High quality randomized controlled trials (RCTs) were selected based on inclusion criteria. RevMan 5.3 were used for the meta-analysis. RESULTS: 12 RCTs containing 1794 patients meet the inclusion criteria. Visual analog scale (VAS) score in CS group decrease more than HA group up to 1 month (p = 0.03) and it shows equal efficacy at 3 months (p = 0.29); HA is more effective than CS at 6 months (p = 0.006). To Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, there is no significant difference for two groups at 3 months (p = 0.29); HA shows greater relative effect than CS at 6 months (p = 0.005). No significant difference is found on proportion of rescue medication use after initiation of treatment (p = 0.58) and proportion of withdrawal for knee pain (p = 0.54). HA and CS exhibit equal efficacy on improvement of active range of knee flexion at 3 months (p = 0.73) and 6 months (p = 0.43). More topical adverse effects occurred in intraarticular HA group when compared with intraarticular CS group. CONCLUSION: Intraarticular CS is more effective on pain relief than intraarticular HA in short term (up to 1 month), while HA is more effective in long term (up to 6 months). Two therapies benefit similarly for knee function improvement. Both two methods are relatively safe, but intraarticular HA causes more topical adverse effects compared with intraarticular CS.


Assuntos
Corticosteroides/administração & dosagem , Ácido Hialurônico/administração & dosagem , Dor Musculoesquelética/tratamento farmacológico , Osteoartrite do Joelho/tratamento farmacológico , Viscossuplementos/administração & dosagem , Feminino , Humanos , Injeções Intra-Articulares , Articulação do Joelho/efeitos dos fármacos , Dor Musculoesquelética/etiologia , Osteoartrite do Joelho/complicações , Medição da Dor , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
11.
Int J Surg ; 39: 57-64, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28110031

RESUMO

BACKGROUND: and purpose: Interspinous process devices (IPD) were widely used for the treatment of lumbar spinal stenosis (LSS). However, whether IPD was superior to bony decompression was still debated. We aimed to compare the clinical outcomes of IPD to bony decompression for LSS. METHODS: PubMed, Cochrane library, Cochrane Central Register of Controlled Trials (CCTR), Ovid Medline, China national knowledge internet database, Wan Fang database were searched in August.8th.2016. Studies were identified using selection criteria and analysed was performed with Review Manager Version 5.3. RESULTS: Four RCTs (seven articles) were included, with 200 patients in the interspinous process devices (IPD) group and 200 patients in bony decompression (DP) group. There was no significant difference in hospital stay time (P = 0.36), VAS leg pain scores (P = 0.83), and complication rates (P = 0.20) for IPD alone versus bony decompression. However, IPD alone showed higher VAS low back pain scores (P = 0.03) and reoperation rates (P < 0.0001) between the two therapy groups. Two studies' results showed the IPD group had lower cost-effectiveness. CONCLUSIONS: Although patients who received IPD may obtain several benefits in the short term, it was associated with higher costs, reoperation rates. Both IPD and bony decompression were acceptable strategies for LSS, but the risks, indications, and costs of IPD should be carefully taken into account before surgery.


Assuntos
Descompressão Cirúrgica/métodos , Disco Intervertebral/cirurgia , Vértebras Lombares/cirurgia , Complicações Pós-Operatórias/etiologia , Estenose Espinal/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Medição da Dor , Ensaios Clínicos Controlados Aleatórios como Assunto , Reoperação , Resultado do Tratamento
12.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 37(2): 215-219, 2017 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-30650276

RESUMO

Objective To observe the effects of notoginsenoside, Panax notoginseng flavonoids (PNF) , Panax notoginseng acid (PNA) , and their mixtures on the expressions of tissue factor (TF) and tissue factor pathway inhibitor 2 (TFPI-2) in rat endometriaum with whole cycle exogenous estrogen inter- vention. Methods Totally 160 female impuberty rats were randomly divided into the blank group (n =40) and the model group (n =120). Rats in the blank group were administered with normal saline by gastroga- vage for 3 weeks, while those in the model group were administered with estradiol valerate suspension. The two interventions lasted for 3 consecutive weeks. After 3 weeks of intervention, rats with asexual cycle were randomly divided into six groups, i.e., the model group, the continuous estrogen group, the No- toginsenoside group, the PNF group, the PNA group, the mixture group. Rats in the model group, the continuous estrogen group, the Notoginsenoside group, the PNF group, the PNA group, the mixture group were respectively administered with normal saline, estrogen, notoginsenoside, PNF, PNA, and mixture of effective Panax notoginseng fractions by gastrogavage for 2 successive weeks. Expression levels of TF, TFPI-2, TF mRNA, and TFPI-2 mRNA in the endometrium were detected 2 weeks later. Re-sults Compared with the blank group, positive expressions of TF and TF mRNA increased, and positive expressions of TFPI-2 and TFPI-2 mRNA decreased in the model group (P <0. 05, P <0. 01). Compared with the model group, the expressions of TF and TF mRNA significantly increased, the expressions of TF- PI-2 and TFPI-2 mRNA significantly decreased in the estrogen group at the end of the 5th week (P < 0. 01). Compared with the model group and the estrogen group, positive expressions of TF and TF mRNA significantly decreased, positive expressions of TFPI-2 and TFPI-2 mRNA significantly increased in the Notoginsenoside group, the PNF group, the PNA group, the mixture group (P <0. 05, P <0. 01). Com- pared with the Notoginsenoside group, positive expressions of TFPI-2 and TFPI-2 mRNA significantly in- creased in the mixture group (P <0. 05). Compared with the PNF group, the expressions of TF and TF mRNA significantly decreased in the Notoginsenoside group and the mixture group (P <0. 01) ; positive expressions of TFPI-2 increased in the mixture group (P <0. 05, P <0. 01). Conclusions The effective fractions of Panax notoginseng could decrease the-expression of TF and increase the expression of TFPI- 2 in rat endometrium with whole cycle exogenous estrogen intervention. They activated blood circulation and arrested bleeding possibly through inhibiting TF, blocking activation of coagulation system, and re- ducing inflammatory response. Meanwhile, it also could strengthen endometrial extracellular matrix, maintain the endometrial stability, thereby reducing endometrial disintegration and bleeding, and being beneficial for endometrium repairing and remodeling.


Assuntos
Endométrio , Estrogênios , Panax notoginseng , Extratos Vegetais , Tromboplastina , Animais , Endométrio/efeitos dos fármacos , Endométrio/metabolismo , Estrogênios/farmacologia , Feminino , Glicoproteínas/metabolismo , Lipoproteínas , Panax notoginseng/química , Extratos Vegetais/farmacologia , Ratos , Tromboplastina/metabolismo
13.
Nat Prod Commun ; 11(6): 805-8, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27534122

RESUMO

Two new isocoumarin derivatives, talaisocoumarins A (1) and B (2), and three new related metabolites, talaflavuols A-C (3-5) were isolated from the wetland soil-derived fungus Talaromyces flavus BYD07-13. Their structures were elucidated by spectroscopic (NMR) and MS analyses. The absolute configurations of 1 and 2 were determined by CD and an Rh2(OCOCF3)4-induced CD method. All compounds were evaluated for cytotoxic and antimicrobial activities. However, none of them showed any activity. The plausible biosynthetic pathways for 1-5 were also proposed.


Assuntos
Isocumarinas/química , Talaromyces/química , Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Anti-Infecciosos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/crescimento & desenvolvimento , Fungos/efeitos dos fármacos , Fungos/crescimento & desenvolvimento , Isocumarinas/metabolismo , Isocumarinas/farmacologia , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Talaromyces/metabolismo
14.
Int J Clin Exp Med ; 8(5): 7930-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26221350

RESUMO

To compare the surgery and conservative treatment of multiple fractured ribs, we designed a randomized controlled trial in the single center of thoracic surgery ward. After admission condition assessment (general clinical evaluation, operation condition assessment, the digital method of pain assessment), the selected multiple fractured rib patients were told to choose surgery or conservative treatment, according to the patient will undergo surgery or conservative treatment. In the acute phase, compared with conservative treatment, patients with mechanical ventilation in time (mechanical ventilation time MV) (3.7 ± 1.4 vs. 9.5 ± 4.3), ICU stay time (8.2 ± 4.3 vs. 14.6 ± 3.2), total hospitalization days (15.3 ± 6.4 vs. 26.5 ± 6.9), the incidence of pneumonia (6.7% vs. 19.1%), mortality (1.3% vs. 5.3%) and pain score on patients (3.3 vs. 5.8) of surgical treatment group were significant lower (P < 0.05). The number of tracheostomy in surgical patients with conservative treatment (4 vs. 7) was no statistically significant difference (P > 0.05). In chronic phase, the surgical patients compared with patients with conservative treatment in the chest wall pain (2.9 ± 1.2 vs. 5.6 ± 1.7), chest wall tension (13.3% vs. 57.3%), dyspnea (5.3% vs. 22.4%) and chest wall deformity rate (4% vs. 93.5%) were lower significantly (P < 0.05). In conclusion, the surgical treatment of multiple fractured ribs could ease the acute chest pain, reduce the mechanical ventilation time and incidence of pneumonia, shorten the hospitalization days and total hospitalization days in the ICU and alleviate the forward chest wall discomfort. The speedy recovery and long-term quality of patients' life had improved significantly.

15.
Angew Chem Int Ed Engl ; 54(32): 9409-13, 2015 Aug 03.
Artigo em Inglês | MEDLINE | ID: mdl-26136346

RESUMO

The first highly diastereo- and enantioselective multicomponent reaction of diazooxindoles, nitrosoarenes, and nitroalkenes using a newly developed hydrogen-bond catalyst has been successfully developed for the efficient construction of a series of spirooxindole derivatives with excellent functional-group tolerance. Spirooxindoles are formed in excellent yields and stereoselectivities, and the method represents an unprecedented approach for trapping the active intermediate with a nitroalkene to form biologically important compounds having three contiguous stereogenic centers with excellent asymmetric induction.


Assuntos
Indóis/química , Compostos de Espiro/química , Catálise , Ligações de Hidrogênio , Indóis/síntese química , Estereoisomerismo , Tioureia/química
16.
Sci Total Environ ; 479-480: 241-6, 2014 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-24561929

RESUMO

The degradation behavior of veterinary antibiotics in soil is commonly studied using the following methods of adding antibiotics to the soil: (i) adding manure collected from animals fed with a diet containing antibiotics, (ii) adding antibiotic-free animal manure spiked with antibiotics and (iii) directly adding antibiotics. No research simultaneously comparing different antibiotic addition methods was found. Oxytetracycline (OTC) was used as a model antibiotic to compare the effect of the three commonly used antibiotic addition methods on OTC degradation behavior in soil. The three treatment methods have similar trends, though OTC degradation half-lives show the following significant differences (P<0.05): manure from swine fed OTC (treatment A)

Assuntos
Antibacterianos/química , Oxitetraciclina/química , Poluentes do Solo/química , Solo/química , Antibacterianos/análise , Esterco , Modelos Químicos , Oxitetraciclina/análise , Microbiologia do Solo , Poluentes do Solo/análise
17.
Dalton Trans ; 41(32): 9737-47, 2012 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-22766614

RESUMO

Ten new chiral coordination polymers, namely, [Ni(L)(H(2)O)(2)] (1), [Co(L)(H(2)O)(2)] (2), [Cd(L)(H(2)O)] (3), [Cd(L)(phen)] (4), [Mn(2)(L)(2) (phen)(2)]·H(2)O (5), [Cd(2)(L)(2)(biim-4)(2)] (6), [Zn(2)(L)(2)(biim-4)(2)] (7), [Cd(L)(pbib)] (8), [Cd(L)(bbtz)] (9) and [Cd(L)(biim-6)] (10), where phen = 1,10-phenathroline, biim-4 = 1,1'-(1,4-butanediyl)bis(imidazole), pbib = 1,4-bis(imidazole-1-ylmethyl)benzene, bbtz = 1,4-bis(1,2,4-triazol-1-ylmethyl)benzene, biim-6 = 1,1'-(1,6-hexanedidyl)bis(imidazole), and H(2)L = (R)-2-(4'-(4''-carboxybenzyloxy)phenoxy)propanoic acid, have been synthesized under hydrothermal conditions. Their structures have been determined by single-crystal X-ray diffraction analyses and further characterized by infrared spectra (IR), powder X-ray diffraction (PXRD), elemental analyses and thermogravimetric (TG) analyses. Compounds 1 and 2 exhibit similar 1D left-handed helical chains, which are further extended into 3D supramolecular structures through O-H···O hydrogen-bonding interactions, respectively. Compound 3 shows a 2D double-layer architecture containing helical chains. Compound 4 features two types of 2D undulated sheets with helical chains, which are stacked in an ABAB fashion along the c direction. Compound 5 possesses a 1D double chain ribbon structure containing unusual meso-helical chains, which is linked by π-π interactions into a 2D supramolecular layer. These layers are further extended by hydrogen-bonding interactions to form a 3D supramolecular assembly. Compounds 6 and 7 are isostructural and exhibit 2D (4(4))-sql networks with helical chains. Neighboring sheets are further linked by C-H···O hydrogen-bonding interactions to generate 3D supramolecular architectures. Compounds 8-10 are isostructural and display 3D 3-fold interpenetrating diamond frameworks with helical chains. The effects of coordination modes of L anions, metal ions and N-donor ligands on the structures of the coordination polymers have been discussed. The luminescent properties of 3, 4 and 6-10 have also been investigated in detail.

18.
BMC Struct Biol ; 9: 67, 2009 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-19852838

RESUMO

BACKGROUND: The carbonic anhydrases (CAs) are involved in inorganic carbon utilization. They have been classified into six evolutionary and structural families: alpha-, beta-, gamma-, delta-, epsilon-, zeta- CAs, with beta-CAs present in higher plants, algae and prokaryotes. The yeast Saccharomyces cerevisiae encodes a single copy of beta-CA Nce103/YNL036W. RESULTS: We determined the crystal structure of Nce103 in complex with a substrate analog at 2.04 A resolution. It assembles as a homodimer, with the active site located at the interface between two monomers. At the bottom of the substrate pocket, a zinc ion is coordinated by the three highly conserved residues Cys57, His112 and Cys115 in addition to a water molecule. Residues Asp59, Arg61, Gly111, Leu102, Val80, Phe75 and Phe97 form a tunnel to the bottom of the active site which is occupied by a molecule of the substrate analog acetate. Activity assays of full length and two truncated versions of Nce103 indicated that the N-terminal arm is indispensable. CONCLUSION: The quaternary structure of Nce103 resembles the typical plant type beta-CAs of known structure, with an N-terminal arm indispensable for the enzymatic activity. Comparative structure analysis enables us to draw a possible tunnel for the substrate to access the active site which is located at the bottom of a funnel-shaped substrate pocket.


Assuntos
Anidrases Carbônicas/química , Saccharomyces cerevisiae/enzimologia , Sequência de Aminoácidos , Sítios de Ligação , Anidrases Carbônicas/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Dimerização , Dados de Sequência Molecular , Estrutura Quaternária de Proteína , Alinhamento de Sequência , Zinco/química
19.
J Chromatogr A ; 1131(1-2): 289-92, 2006 Oct 27.
Artigo em Inglês | MEDLINE | ID: mdl-16979177

RESUMO

A capillary electrophoresis coupling with indirect chemiluminescence detection method for the simultaneous determination of benserazide and levodopa has been developed. The detection interface was improved to simplify the capillary electrophoresis-chemiluminescence (CE-CL) system and the features of this improved interface were illustrated in this paper. The CE-CL conditions for the simultaneous determination of benserazide and levodopa were optimized. Under the optimal conditions, the CL intensity was linear with concentrations of levodopa in the range of 1.0 to 100.0 microg ml(-1), and benserazide in the range of 10.0 to 1,000 microg ml(-1), respectively. The detection limits (S/N=3) in turn were 1.85 microg ml(-1) for BS and 0.12 microg ml(-1) for L-dopa with relative standard deviations of less than 3%. The proposed method has been successfully applied to the determination of benserazide and levodopa in medopar tablets and spiked urine samples, demonstrating the feasibility and reliability of the proposed method.


Assuntos
Benserazida/análise , Eletroforese Capilar/métodos , Levodopa/análise , Medições Luminescentes/métodos , Eletroforese Capilar/instrumentação , Medições Luminescentes/instrumentação , Reprodutibilidade dos Testes
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