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1.
Opt Express ; 32(8): 13527-13542, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38859320

RESUMO

We report on the growth, polarized spectroscopy and first laser operation of an orthorhombic (space group Pnma) Tm3+,Ho3+-codoped gadolinium orthoscandate (GdScO3) perovskite-type crystal. A single crystal of 3.76 at.% Tm, 0.35 at.% Ho:GdScO3 was grown by the Czochralski method. Its polarized absorption and fluorescence properties were studied revealing a broadband emission around 2 µm. The parameters of the Tm3+ ↔ Ho3+ energy transfer was quantified, P28 = 1.30 × 10-22 cm3µs-1, and P71 = 0.99 × 10-23 cm3µs-1, and the thermal equilibrium lifetime was measured to be 3.5 ms. The crystal-field splitting of Tm3+ and Ho3+ multiplets in Cs symmetry sites of the perovskite structure was determined by low-temperature spectroscopy and the mechanism of spectral line broadening is discussed. The continuous-wave Tm,Ho:GdScO3 laser generated 1.16 W at ∼2.1 µm with a slope efficiency of 50.5%, a laser threshold of 184 mW, a linear laser polarization (E || c) and a spatially single-mode output. The Tm,Ho:GdScO3 crystal is promising for broadly tunable and femtosecond mode-locked lasers emitting above 2 µm.

2.
Am J Hematol ; 99(4): 780-784, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38357757

RESUMO

Kaplan-Meier curve depicting overall survival from CLL treatment start by race. For patients with CLL, no overall survival difference was observed between races in this real-world US database.


Assuntos
Leucemia Linfocítica Crônica de Células B , Humanos , Estudos de Coortes
3.
Appl Nurs Res ; 67: 151627, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36116865

RESUMO

BACKGROUND: Before pursuing randomized controlled trials to determine intervention effectiveness and translating interventions into clinical practice, the need for a specific intervention within a particular population must be established. This need can be determined by using established cut scores on validated measures of relevant constructs. AIM: This study examined differences on caregiver burden and resourcefulness among family caregivers of adults with various health conditions to determine their need for resourcefulness training. METHODS: This cross-sectional study sampled 234 caregivers of persons with amyotrophic lateral sclerosis, cancer, dementia, mental illness, Parkinson's disease, stroke, traumatic brain injury, and multiple or other conditions. They completed validated measures of caregiver burden and resourcefulness. Differences were examined using analysis of variance. Need for intervention was evaluated by comparison with established cut scores. RESULTS: Caregivers differed significantly on caregiver burden (F = 2.46; p = .014) and resourcefulness (F = 2.08; p = .038). Across the groups, average caregiver burden scores indicated severe to very severe burden with caregivers of persons with stroke scoring the highest (M = 26.33) and a moderate or greater need for resourcefulness with the greatest needs in caregivers of persons with stroke, traumatic brain injury, and dementia (M's = 74.83, 72.31, and 77.12). CONCLUSIONS: The findings suggest the need for intervention among all family caregiver groups to reduce their burden, with caregivers of persons with stroke showing greatest need. Specifically regarding resourcefulness training, the needs of family caregivers differed by care recipient condition. Using pre-determined cut scores on established, relevant measures provides support for proposing clinical trials, translation into practice, and intervention sustainability.


Assuntos
Lesões Encefálicas Traumáticas , Demência , Acidente Vascular Cerebral , Adulto , Cuidadores/educação , Estudos Transversais , Humanos
4.
Aquac Nutr ; 2022: 6746201, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36860431

RESUMO

This study evaluated the effect of dietary rapeseed meal (RM) and hydrolyzable tannin on grass carp (Ctenopharyngodon idella) and determined the possible role of tannin on health when RM was added to the diet. Eight diets were formulated. Four were semipurified-diets with 0, 0.75, 1.25, and 1.75% hydrolyzable tannin (T0, T1, T2, and T3), and the other four were practical diets containing 0, 30, 50, and 70% RM (R0, R30, R50, and R70), which had similar tannin contents as semipurified-diets. After the 56 d feeding trial, the antioxidative enzymes and relative biochemical indexes showed a similar tendency in practical and semipurified groups. In hepatopancreas, superoxide dismutase (SOD) and catalase (CAT) activities increased with RM and tannin levels, respectively, while glutathione (GSH) content and glutathione peroxidase (GPx) activity increased. Malondialdehyde (MDA) content increased and decreased in T3 and R70, respectively. In the intestine, MDA content and SOD activity increased with RM and tannin levels, while GSH content and GPx activity decreased. The expression levels of interleukin 8 (IL-8) and interleukin 10 (IL-10) were upregulated with RM and tannin levels, and the Kelch-like ECH-associated protein 1 (Keap1) expression was upregulated in T3, whereas it was downregulated in R50. This study demonstrated that 50% of RM and 0.75% of tannin induced oxidative stress, injured hepatic antioxidant ability, and resulted in intestinal inflammation in grass carp. Therefore, the tannin in rapeseed meal cannot be neglected in aquatic feeding.

5.
Pak J Med Sci ; 37(5): 1524-1531, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34475942

RESUMO

BACKGROUND: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a cause of coronavirus disease 2019 (COVID-19), mainly targets the respiratory system. However, recent studies also show its role in causing gastrointestinal hemorrhage, potentially affecting morbidity and mortality-related outcomes of the patients. There is still no consensus on the risk factors, characteristics, and the overall outcome of the gastrointestinal hemorrhage in COVID-19 patients. The main aim of this study was to summarize current evidence, assessing risk factors that promote the onset of gastrointestinal hemorrhage in COVID-19 patients, and to compare the incidences of the different sites of gastrointestinal lesions, the events of abdominal pain, diarrhea, intensive care unit admissions, and mortality between COVID-19 patients with or without gastrointestinal bleeding. METHODS: A search of the academic literature was performed according to the PRISMA guidelines across five databases i.e., Web of Science, EMBASE, CENTRAL, Scopus, and MEDLINE. A random-effect meta-analysis was conducted to analyze the influence of the history of drugs consumption, gastrointestinal bleeding, the different incidence of gastrointestinal lesions, events of abdominal pain, intensive care unit (ICU) admission, and mortality between COVID-19 patients with/without gastrointestinal bleeding. RESULTS: Out of 458 studies, three eligible studies with 663 participants (mean age: 69.7 ± 4.3 years) were included. A meta-analysis showed a medium-to-large influence of the history of gastrointestinal bleeding (Hedge's g: 1.01) and anticoagulant drug consumption (g: 0.33) on the gastrointestinal bleeding in COVID-19 patients. Moreover, the incidence of gastroduodenal ulcers was higher as compared to esophagitis (37.5% versus 9.9%). CONCLUSIONS: The study provides preliminary evidence regarding the risk factors associated with the onset of gastrointestinal hemorrhage among COVID-19 patients. The study also outlines the characteristics and the outcomes of gastrointestinal hemorrhage in COVID-19 patients.

6.
Pak J Med Sci ; 37(4): 1104-1110, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34290791

RESUMO

OBJECTIVES: We designed this prospective observational study to clarify the associations between dialysate IL-6, a marker of ongoing peritoneal inflammation, Tie2, an important factor in angiogenesis in the peritoneum, and a high peritoneal solute transport rate (PSTR) in patients undergoing peritoneal dialysis (PD) and to investigate their outcome predictive roles. METHODS: A total of 60 stable continuous ambulatory peritoneal dialysis (CAPD) patients from a single center in China were analyzed in this prospective study. We measured dialysate levels of IL-6 and Tie-2 using ELISAs. Our primary study endpoint was all-cause mortality with 10 years' follow-up. RESULTS: For the evaluation of PSTR, we used the Dialysis/Plasma creatinine (D/Pcr) ratio. We subdivided the patients into two groups for statistical evaluation: low and low average D/Pcr (<0.64; L/A), and high and high average D/Pcr (≥0.65; H/A) transporters. The mean levels of dialysates IL-6 (21.71 ± 8.88 pg/mL) and Tie-2 (1.23 ± 0.43 ng/mL) were significantly higher in the H/A (high and high average, group than those in the L/A group (13.94 ± 5.43 pg/mL, p<0.001 and 0.95 ± 0.43 ng/mL, p=0.019; respectively). Moreover, IL-6 and Tie-2 were positively correlated with D/Pcr (r=0.366, p=0.004 and r=0.402, p=0.001; respectively). Both dialysates IL-6 and Tie-2 were independent determinants of a high peritoneal solute transport rate. After follow-up for 42.65±18.08 months, 30 patients (50.0%) had died. An increased D/Pcr increased the risk of all-cause mortality in patients with CAPD (p=0.018), but the dialysates IL-6 and Tie2 were not independent predictors of all-cause mortality (p>0.05). CONCLUSION: Our results suggest that patients undergoing CAPD have a high peritoneal solute transport status with local peritoneal inflammation and angiogenesis. Increased D/Pcr is a relative risk factor for mortality and technique failure in patients undergoing CAPD.

7.
J Org Chem ; 84(7): 4473-4477, 2019 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-30882223

RESUMO

Heliaquanoid A (1), the first exo-2,4-linked Diels-Alder adduct between a pseudoguaianolide dienophile and a guaianolide diene, and heliaquanoids B-E (2-5), four new 2,4-linked Diels-Alder adducts between a xanthanolide dienophile and a guaianolide diene, were isolated from stems and leaves of Inula helianthus-aquatica. Their structures were determined by NMR spectroscopy, a modified Mosher's method, electronic circular dichroism, and X-ray diffraction analysis. Compounds 2 and 3 exhibited moderate cytotoxic activities against HL-60 cells with IC50 values of 7.5 and 4.9 µM, respectively.


Assuntos
Inula/química , Sesquiterpenos/química , Células A549 , Antineoplásicos/química , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Dimerização , Ensaios de Seleção de Medicamentos Antitumorais , Células HL-60 , Helianthus/química , Humanos , Células MCF-7 , Modelos Moleculares , Ressonância Magnética Nuclear Biomolecular , Sesquiterpenos/isolamento & purificação , Sesquiterpenos/farmacologia
8.
J Nat Prod ; 82(10): 2859-2869, 2019 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-31557016

RESUMO

Nine new cycloartane triterpenoids (1, 2, 4, 7, 8, 12, 15, 17, and 18) and two new rare tetraterpenoids (24 and 25) formed via a [4 + 2] Diels-Alder cycloaddition between a lanostane triterpenoid and a monoterpenoid, along with 14 previously known triterpenoids, were isolated from the bark of the branches of Abies chensiensis. The structures and absolute configurations of new compounds were elucidated based on spectroscopic data, X-ray diffraction analysis, and electronic circular dichroism. Some of the isolates were evaluated for their antibacterial activity by determining their minimum inhibitory concentrations and growth inhibition curves and examining for morphological alterations. Among the compounds tested, the new cycloartane triterpenoid 8 was the most active against Bacillus subtilis. Thus, morphological alterations of B. subtilis on treatment with 8 were observed by scanning electron microscopy, showing that the cells were irregular, wrinkled, and disrupted.


Assuntos
Abies/química , Antibacterianos/isolamento & purificação , Carotenoides/isolamento & purificação , Triterpenos/isolamento & purificação , Antibacterianos/química , Antibacterianos/farmacologia , Bacillus subtilis/efeitos dos fármacos , Carotenoides/química , Carotenoides/farmacologia , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Conformação Molecular , Triterpenos/química , Triterpenos/farmacologia
9.
J Nat Prod ; 82(9): 2568-2579, 2019 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-31503485

RESUMO

Thirteen new labdane-type diterpenoids 1-6, 9-11, 13, 14, 18, and 19 and seven known ones were isolated from the aerial parts of Leonurus japonicus. Compounds 1-5 represent rare examples of labdane-type diterpenoids, of which compounds 1-4 carry an N-chain linked at C-7 in their B-ring and compound 5 featured an α,ß-unsaturated-γ-lactam moiety. The structures and absolute configurations of these new diterpenoids were characterized by a combination of spectroscopic techniques, X-ray crystallography, electronic circular dichroism, and calculated specific rotations. The plant-growth regulatory activity of these compounds on the growth of the roots and shoots of Lactuca sativa and Lolium perenne seedlings were evaluated. Compound 3 showed a broad-spectrum inhibitory activity with the inhibition rates ranging from 60 to 83.5% at a concentration of 200 µg/mL, which were as active as those of glyphosate. Compound 8 had a selective inhibitory activity against the growth of the roots of L. perenne seedlings with an inhibition rate of 81.7%. However, compounds 11 and 16 exhibited significant stimulation effects on the roots of L. sativa with stimulation rates of 59.8 and 65.3%, respectively. In addition, compounds 3 and 8 exhibited inhibitory effects on the germination of L. perenne seeds.


Assuntos
Diterpenos/farmacologia , Leonurus/química , Reguladores de Crescimento de Plantas/farmacologia , Cristalografia por Raios X , Diterpenos/química , Diterpenos/isolamento & purificação , Estrutura Molecular , Reguladores de Crescimento de Plantas/isolamento & purificação , Análise Espectral/métodos
10.
Bioorg Chem ; 93: 103256, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31586706

RESUMO

A phytochemical investigation to obtain chemical components with potential anti-inflammatory activity from E. hylonoma led to the isolation of nine new ent-isopimarane diterpenoids (1 and 3-10), a new ent-rosane diterpenoid (11), along with eight known ones (2 and 12-18) using various chromatographic techniques. Compounds 3, 4, 5, and 10 were rare examples of the epoxy-ent-isopimarane. The structures of these new compounds were confirmed by extensive spectroscopic data, crystal X-ray diffraction analysis, and electronic circular dichroism. And the isolates were evaluated for their inhibitory effects on nitric oxide production induced by lipopolysaccharide in RAW 264.7 cells. The results showed that compounds 2 and 12 exhibited noteworthy inhibitory effects against NO production with IC50 values of 7.12 and 12.73 µM, respectively, which were better than positive control (IC50 = 41.41 µM). The possible mechanism that compounds 2 and 12 could inhibit NO production was investigated by the Western blotting experiments.


Assuntos
Diterpenos/química , Euphorbia/química , Animais , Anti-Inflamatórios , Macrófagos/efeitos dos fármacos , Camundongos , Modelos Moleculares , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Raízes de Plantas/química , Células RAW 264.7 , Relação Estrutura-Atividade
11.
J Prosthet Dent ; 122(4): 383-388, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30982624

RESUMO

STATEMENT OF PROBLEM: High rates of veneering chipping are a common prosthodontic complication of restorations with a titanium framework. A new bio high-performance polymer (BioHPP) based on polyetheretherketone (PEEK) has been introduced for denture superstructures. Clinical reports suggest that BioHPP could be used as an alternative framework material to support complete-arch restorations. However, peer-reviewed information is lacking regarding the performance of BioHPP as a framework material for implant-supported screw-retained fixed dental prostheses (FDPs) veneered with composite resin. PURPOSE: The purpose of this in vitro study was to evaluate and compare the bond strength of modified PEEK (BioHHP) and titanium with a veneering composite resin and compare the marginal fit and fracture resistance of implant-supported screw-retained FDPs fabricated by using computer-aided design and computer-aided manufacturing (CAD-CAM) frameworks veneered with composite resin. MATERIAL AND METHODS: A composite resin was bonded to 2 framework materials (n=20/group): pure titanium (Ti) and BioHPP (Bi). The shear bond strength (SBS) was determined after 24-hour wet storage. Furthermore, 20 3-unit CAD-CAM BioHPP and titanium frameworks were fabricated (n=10/group). The marginal fit between frameworks and abutments was evaluated by scanning electron microscopy by using the single-screw test. After thermocycling and mastication simulation, the fracture resistance of FDPs veneered with the composite resin was examined. The independent sample t test was used to evaluate differences (α=.05). RESULTS: Significantly higher shear bond strengths were obtained in group Bi (31.1 ±3.5 MPa) than in group Ti (20.5 ±1.8 MPa). The mean marginal gap width was 19 ±4 µm in group Bi and 16 ±6 µm in group Ti. Statistical tests showed no significant differences (P>.05). After loading, veneering chipping was observed at a load of 1960 ±233 N in group Ti. Although the BioHPP frameworks fractured at 1518 ±134 N, no chipping occurred. CONCLUSIONS: The bond strength of BioHPP with the composite resin was greater than that of titanium. CAD-CAM BioHPP frameworks exhibit good marginal fit and fracture resistance. BioHPP may be a suitable alternative to metal as a framework to be veneered with composite resin.


Assuntos
Prótese Dentária Fixada por Implante , Titânio , Resinas Compostas , Desenho Assistido por Computador , Materiais Dentários , Porcelana Dentária , Teste de Materiais , Polímeros , Zircônio
12.
Zhongguo Zhong Yao Za Zhi ; 42(2): 303-306, 2017 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-28948735

RESUMO

We have carried out the chemical investigation on the roots of Alangium chinense. The chemical constituents from the roots of A.chinense were isolated and purified by various chromatographic techniques, such as silica gel, MCI-Gel resin, Sephadex LH-20 and high performance liquid chromatography. As a result, three alkaloids (1-3) were isolated from 90% EtOH extracts of the roots of this plant. Their structures were elucidated by physical-chemical properties and spectral data. Among them, compound 1 is a new compound, determined as 8-hydroxy-3-hydroxymethyl-6,9-dimethyl-7H-benzo[de]isoquinolin-7-one. Cytotoxicity of the compounds was evaluated by the MTT method. Compound 1 displayed cytotoxicity against NB4, A-549, SHSY5Y, PC-3 and MCF-7 cell lines with IC50 values of 4.2, 3.5, 5.7, 2.8 and 3.9 µmol•L⁻¹, respectively.


Assuntos
Alangiaceae/química , Alcaloides/isolamento & purificação , Raízes de Plantas/química , Linhagem Celular Tumoral , Humanos , Compostos Fitoquímicos/isolamento & purificação
13.
J Asian Nat Prod Res ; 18(12): 1115-1121, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27314454

RESUMO

Phytochemical investigations on the ethanol extract of the twigs of Garcinia tetralata resulted in the isolation of three new biphenyls, tetralatabiphenyls A-C (1-3), along with three known biphenyl derivatives (4-6). Structural elucidations of 1-3 were performed by spectroscopic methods such as 1D and 2D NMR spectra, in addition to high-resolution mass spectra. Compounds 1-6 were also evaluated for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compound 3 showed high anti-TMV activity with inhibition rate of 31.1%. Compounds 1, 2, and 4-6 also showed modest anti-TMV activities with inhibition rates in the range of 18.9-24.5%, respectively.


Assuntos
Antivirais/isolamento & purificação , Antivirais/farmacologia , Compostos de Bifenilo/isolamento & purificação , Compostos de Bifenilo/farmacologia , Garcinia/química , Vírus do Mosaico do Tabaco/efeitos dos fármacos , Antivirais/química , Compostos de Bifenilo/química , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Caules de Planta/química
14.
Zhongguo Zhong Yao Za Zhi ; 41(17): 3256-3259, 2016 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-28920379

RESUMO

For the purpose of finding new bioactive agents from ethnic medicines, the chemical study on Dai Medicine Cassia occidentalis was carried out. The chemical constituents from the seeds of C. occidentalis were isolated by column chromatographic methods on silica gel, MCI-Gel resin, Sephadex LH-20, and high performance liquid chromatography. Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. The cytotoxicity of the compound for NB4, A549, SHSY5Y, PC3, and MCF7 cells line was also assayed by using the MTT method. Two sesquiterpenes (1 and 2) were isolated from this plant. Compound 1 is a new compound and named as methyl 6-(hydroxymethyl)-4-isopropyl-7-methoxynaphthalene-1-carboxylate. Compound 1 also displayed high cytotoxicity with the tested cancer cell-lines.


Assuntos
Sementes/química , Senna/química , Sesquiterpenos/isolamento & purificação , Humanos , Células MCF-7 , Compostos Fitoquímicos/isolamento & purificação
15.
Zhongguo Zhong Yao Za Zhi ; 41(23): 4389-4392, 2016 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-28933117

RESUMO

The phytochemistry investigation on the Cassia occidentalis, a Dai Medicine, was carried out. The C. occidentalis was extracted with ethanol and then partitioned with EtOAc. The EtOAc soluble materials were subjected repeatedly to column chromatography on silica gel and preparative RP-HPLC, leading to isolation of a nor-sesquiterpene, 3-isopropyl-1,6-dimethoxy-5-methyl-naphthalen-7-ol (1), and a sesquiterpene, 2,7-dihydroxy-4-isopropyl-6-methyl-naphthalene-1-carbaldehyde (2). Their structures were determined by means of spectroscopic studies. Compound 1 is a new compound. Compound 2 is also isolated from C. occidentalis for the first time. In addition, the cytotoxicity of compound 1 for NB4, A549, SHSY5Y, PC3, and MCF7 cells line was assayed by using the MTT method, and it displayed potential cytotoxicity for the tested cancer cell-line with IC50 valves of (1.8±0.2), (1.2±0.2), (0.9±0.1), (2.2±0.3), (2.6±0.3) µmol•L⁻¹, respectively.


Assuntos
Senna/química , Sesquiterpenos/isolamento & purificação , Linhagem Celular Tumoral , Humanos , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/farmacologia , Extratos Vegetais/química , Sesquiterpenos/farmacologia
16.
Zhongguo Zhong Yao Za Zhi ; 41(9): 1646-1648, 2016 May.
Artigo em Chinês | MEDLINE | ID: mdl-28891613

RESUMO

A new isoindole alkaloid (1), has been isolated from the leaves of Cassia siamea by using various chromatographic techniques. Compound 1 is a new compound, determined as 5-(hydroxymethyl)-2-methyl-6-prenylisoindolin-1-one, and it displayed cytotoxicity against NB4, A549, SHSY5Y, PC3 and MCF7 cell lines with IC50 values of 3.2,4.6,2.8,6.4, 2.5 µmol•L⁻¹, respectively.


Assuntos
Alcaloides/isolamento & purificação , Cassia/química , Isoindóis/isolamento & purificação , Folhas de Planta/química , Linhagem Celular Tumoral , Humanos
17.
Zhongguo Zhong Yao Za Zhi ; 41(14): 2652-2654, 2016 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-28905601

RESUMO

A new furan-2-carboxylic acid, 5-[3-(hydroxymethyl)-4,5-dimethoxyphenyl]-3-methylfuran-2-carboxylic acid(1),has been isolated from the bark of Cassia alata by using various chromatographic techniques. It displayed cytotoxicity against NB4, A549, SHSY5Y, PC3 and MCF7 cell lines with IC50 values of 2.5, 1.2, 2.2, 3.6 and 1.9 µmol•L⁻¹, respectively.


Assuntos
Ácidos Carboxílicos/isolamento & purificação , Cassia/química , Furanos/isolamento & purificação , Casca de Planta/química , Compostos Fitoquímicos/isolamento & purificação , Extratos Vegetais
19.
J Chem Phys ; 142(21): 212441, 2015 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-26049461

RESUMO

Two-dimensional infrared (2D-IR) spectroscopy was performed on Vaska's complex (VC) and its oxygen adduct (V C-O2) in binary solvent mixtures of chloroform or benzyl alcohol in d6-benzene. The second order rate constants for oxygenation were also measured in these solvent mixtures. The rate constant in chloroform mixtures is linear with mole fraction within the error of the measurements but changes nonlinearly in benzyl alcohol mixtures, displaying a preference for the alcohol over benzene. The rate constants were compared with FTIR spectra of the carbonyl ligand and the frequency-frequency correlation function of this mode determined by 2D-IR. The line shape broadening mechanisms of the linear spectra of the CO bound to VC and V C-O2 are similar to those previously reported for V C-I2. There is a particularly strong correlation between rate constants and homogeneous linewidths of the carbonyl vibration on the V C-O2 product state. Concurrently, the FTIR spectra and spectral diffusion observed by 2D-IR corroborate an increase in solvent heterogeneity around the product. We interpret these results in the context of the potential role of solvent dynamics in facilitating chemical reactivity.

20.
Biol Reprod ; 90(6): 125, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24790158

RESUMO

In conventional in vitro fertilization (IVF), complete failure of fertilization occurs in 5% to 15% of treatments. Although the causes may be unclear, sperm defects appear to be the major contributor. However, a convincing test is not yet available that can predict the risk of fertilization failure. In this study, we found that germinal angiotensin-converting enzyme (gACE) (also called testicular ACE) was undetectable in sperm from patients who had total fertilization failure (TFF) and lower fertilization rates (LFRs) by IVF based on Western blot and indirect immunofluorescence analyses. Additionally, almost all of the patients without gACE on sperm (23 of 25) manifested a TT genotype of the rs4316 single-nucleotide polymorphism of ACE. Overall, our results indicate that the absence of gACE expression is responsible for TFF and LFRs by IVF. The rs4316 polymorphism of ACE might be associated with infertility in those patients. We conclude that sperm lacking gACE may be recognized before commencing IVF and that the patients may be directed instead to consider intracytoplasmic sperm injection.


Assuntos
Fertilização in vitro , Infertilidade Masculina , Peptidil Dipeptidase A/metabolismo , Injeções de Esperma Intracitoplásmicas , Espermatozoides/enzimologia , Adulto , Domínio Catalítico/genética , Feminino , Fertilização/fisiologia , Testes Genéticos , Genótipo , Humanos , Infertilidade Masculina/enzimologia , Infertilidade Masculina/genética , Infertilidade Masculina/terapia , Masculino , Recuperação de Oócitos , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/genética , Polimorfismo de Fragmento de Restrição , Regiões Promotoras Genéticas/genética , Testículo/citologia , Testículo/enzimologia , Falha de Tratamento
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