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1.
Zhonghua Yi Xue Za Zhi ; 103(18): 1363-1366, 2023 May 16.
Artigo em Chinês | MEDLINE | ID: mdl-37020176

RESUMO

With the wide application of artificial intelligence (AI) technology in clinical practice, more and more legal problems need to be solved. At present, although the legal status of AI is still controversial in academic and practical circles, its infringement risk in clinical diagnosis and surgery cannot be avoided. On the basis of the distinction between strong and weak AI liability subjects, those who meet the requirements of infringement, damage consequence, causal relationship, subjective fault, etc., can constitute tort liability, but the existence of exemption causes can also exempt liability. In addition to the ex post accountability of tort liability, it is also necessary to establish a complete administrative legal regulation system. At present, China needs to explore and establish the classification registration system, compulsory insurance system and reserve system of AI as soon as possible, so as to strengthen the legal regulation of the whole process of AI clinical application before, during and after the event.


Assuntos
Inteligência Artificial , Responsabilidade Legal , Humanos , China
2.
Zhonghua Er Ke Za Zhi ; 60(9): 888-893, 2022 Sep 02.
Artigo em Chinês | MEDLINE | ID: mdl-36038297

RESUMO

Objective: To evaluate the short-and mid-term efficacy of pediatric kidney transplantation and the risk factors for kidney graft and recipient. Methods: The baseline data and postoperative complications of pediatric donors and recipients of 284 kidney transplants were retrospectively analyzed in the Department of Kidney Transplantation in the First Affiliated Hospital of Zhengzhou University from August 2010 to May 2021 and all subjects were followed up until December 31, 2021. According to the survival status of donors and recipients, they were divided into the graft-loss group and the graft-survival group, and the recipient death group and survival group, respectively. Univariate comparison between groups was performed by Log-rank test, and Cox proportional risk model was used to explore the independent risk factors for the graft and recipient survival. Results: Among the 284 children recipients, 184 cases (64.8%) were male and 100 cases(35.2%) were female, and 19 cases (6.7%) were living relative donor renal transplantation, 19 cases (6.7%) were preemptive transplantation, and 8 cases were secondary transplantation. The age of 284 recipients at the time of transplantation was 13.0 (9.0, 15.0) years, among whom 29 cases aged 0-6 years, 96 cases aged 7-11 years old, and 159 cases aged 12-18 years. The 1, 3, and 5 year survival rates were 92.3%, 88.9% and 84.8% for the kidney grafts, and were 97.1%, 95.6% and 94.4% for the recipients, respectively. Multivariate analysis showed postoperative acute rejection (HR=3.14, 95%CI 1.38-7.15, P=0.006) and perioperative vascular complications (HR=4.73, 95%CI 2.03-11.06, P<0.001) were independent risk factors for the survival of kidney graft. Postoperative infection (HR=14.23, 95%CI 3.45-58.72, P<0.001) was an independent risk factor for the postoperative mortality of recipients. Conclusions: Pediatric kidney transplantation shows a good short-and mid-term prognosis. Postoperative acute rejection and perioperative vascular complications are the risk factors for the survival of kidney graft, and postoperative infection is the risk factor affecting the survival of recipient.


Assuntos
Transplante de Rim , Criança , Feminino , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Transplante de Rim/efeitos adversos , Doadores Vivos , Masculino , Complicações Pós-Operatórias , Prognóstico , Estudos Retrospectivos , Fatores de Risco
3.
Eur Rev Med Pharmacol Sci ; 25(8): 3149, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33928596

RESUMO

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "Long non-coding RNA OR3A4 facilitates cell proliferation and migration in colorectal cancer through the Wnt/ß-catenin signaling pathway, by W. Sun, G.-R. Chen, J. Wang, X.-Y. Yu, X.-F. Hao, M.-Y. Hu, published in Eur Rev Med Pharmacol Sci 2020; 24 (10): 5360-5366-DOI: 10.26355/eurrev_202005_21319-PMID: 32495870" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/21319.

4.
Sci Adv ; 7(2)2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33523962

RESUMO

Equilibrium condensation of solar gas is often invoked to explain the abundance of refractory elements in planets and meteorites. This is partly motivated, by the observation that the depletions in both the least and most refractory rare earth elements (REEs) in meteoritic group II calcium-aluminum-rich inclusions (CAIs) can be reproduced by thermodynamic models of solar nebula condensation. We measured the isotopic compositions of Ce, Nd, Sm, Eu, Gd, Dy, Er, and Yb in eight CAIs to test this scenario. Contrary to expectation for equilibrium condensation, we find light isotope enrichment for the most refractory REEs and more subdued isotopic variations for the least refractory REEs. This suggests that group II CAIs formed by a two-stage process involving fast evaporation of preexisting materials, followed by near-equilibrium recondensation. The calculated time scales are consistent with heating in events akin to FU Orionis- or EX Lupi-type outbursts of eruptive pre-main-sequence stars.

5.
Zhonghua Yi Xue Za Zhi ; 100(43): 3407-3413, 2020 Nov 24.
Artigo em Chinês | MEDLINE | ID: mdl-33238670

RESUMO

Objective: To explore the histopathology, monocytes phenotypes and brain mRNA transcription of angiogenic and atherogenic factors preliminarily in spontaneous hypertensive rats (SHRs) fed with high salt diet and subjected to chronic focal hypoperfusion. Methods: A total of 21 SHRs were randomly assigned into SHR with normal diet (SHR-ND group, n=7), SHR fed with high salt (8%) chows (SHR-HSD group, n=14) groups. After induction of high salt diet for 20 weeks, unilateral carotid artery occlusion was applied to one half of SHR-HSD (SHR-HSD-UCAO, n=7) group for 10 weeks to mimic chronic focal cerebral hypoperfusion. The neuropathology, monocytes phenotypes and brain transcription of fibroblast growth factor (FGF-b), platelet-derived endothelial cell growth factor (PD-ECGF), angiogenin (ANG), transforming growth factor-ß (TGF-ß) and vascular endothelial growth factor A (VEGF-A) among three groups were compared. Results: The systolic blood pressure ((246±12) mmHg vs (220±16) mmHg, P=0.0291, 1 mmHg=0.133 kPa) and diastolic blood pressure ((189±15) mmHg vs (164±12) mmHg, P=0.0143) of SHR-HSD group were elevated significantly compared with those of SHR-ND group. Compared with normotensive Wistar-Kyoto (WKY), SHR-ND, SHR-HSD and SHR-HSD-UCAO groups demonstrated lipohyalinosis, vessel wall thickening, lumen narrowing and multiple enlarged perivascular space and diffuse disarrangement of nerve fiber and myelin vacuolation in corpus callosum pathologically. The ratio of CD11b(+) CD68(+) monocytes in peripheral blood of SHR-HSD group was higher compared with both SHR-ND and SHR-HSD-UCAO groups (P=0.000 8). The mean inflorescence index (MFI) of CD86 and CD206 showd considerable decline in SHR-HSD-UCAO group compared with those of SHR-HSD group (P=0.018 7 and 0.016 8, respectively). The CD86 MFI of CD11b+CD68+ monocytes in SHR-HSD-UCAO group was remarkably higher than that of SHR-ND and SHR-HSD groups (P=0.000 5). Compared with SHR-ND and SHR-HSD groups, the brain mRNA transcription of angiogenic factors including PD-ECGF and ANG were down-regulated (P=0.004 6 and 0.000 2, respectively), while the atherogenic factors including TGF-ß and VEGF-A were up-regulated in SHR-HSD-UCAO group (P<0.000 1 and P=0.045, respectively). Conclusion: SHR-HSD-UCAO group shares the pathophysiological characteristics with advanced stage arteriosclerotic cerebral small vessel disease (aCSVD), including neuropathology, imbalanced circulating monocytes phenotypes and down-regulated angiogenic factors.


Assuntos
Hipertensão , Fator A de Crescimento do Endotélio Vascular , Animais , Pressão Sanguínea , Dieta , Ratos , Ratos Endogâmicos SHR , Ratos Endogâmicos WKY
6.
Clin Exp Dermatol ; 45(7): 836-840, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32789979

RESUMO

Psoriasis is a chronic skin disease characterized by recurrent inflammation, and is increasingly being recognized as a systemic inflammatory disorder, which is associated with cardiovascular events, metabolic syndrome, diabetes, obesity and hypertension. Recent findings have suggested a greater risk of hypertension, particularly difficult-to-control hypertension, in patients with severe psoriasis. Additionally, abnormal activation of immune cells with overexpression of pathogenic cytokines in psoriasis, leading to immune cascade, oxidative injury and collagen deposition in arteries, may further contribute to vascular stiffening and hypertension. However, studies have demonstrated beneficial effects of antipsoriatic drugs on blood pressure and the cardiovascular system, including immunosuppressants and biological reagents targeting tumour necrosis factor-α, interleukin (IL)-17A and the IL-12/23 p40 subunit. This review summarizes the mechanisms underlying the impact of systemic inflammation on skin and arteries, and assesses the epidemiological and clinical links between psoriasis and hypertension.


Assuntos
Anti-Inflamatórios/uso terapêutico , Fatores Biológicos/farmacologia , Hipertensão/complicações , Imunossupressores/farmacologia , Psoríase/tratamento farmacológico , Fatores Biológicos/efeitos adversos , Doenças Cardiovasculares/complicações , Citocinas/imunologia , Citocinas/metabolismo , Complicações do Diabetes/epidemiologia , Humanos , Hipertensão/epidemiologia , Imunossupressores/efeitos adversos , Inflamação/imunologia , Inflamação/patologia , Interleucina-12/metabolismo , Interleucina-17/metabolismo , Síndrome Metabólica/complicações , Obesidade/complicações , Prevalência , Psoríase/imunologia , Recidiva , Medição de Risco , Índice de Gravidade de Doença , Pele/patologia , Fator de Necrose Tumoral alfa/efeitos dos fármacos , Rigidez Vascular/efeitos dos fármacos , Rigidez Vascular/imunologia
7.
Eur Rev Med Pharmacol Sci ; 24(10): 5360-5366, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32495870

RESUMO

OBJECTIVE: Colorectal cancer (CRC) remains one of the most ordinary cancers worldwide. Recently, researches have suggested the important role of long noncoding RNAs (lncRNAs) in the progression of tumorigenesis. This study aims to identify how lncRNA OR3A4 functions in the development of CRC. PATIENTS AND METHODS: OR3A4 expressions in 54 paired CRC tissues and CRC cell lines were detected by Real Time-quantitative Polymerase Chain Reaction (RT-qPCR). Moreover, the in vitro functions of OR3A4 in CRC cells were identified by performing proliferation assay, wound healing assay, and transwell assay. Besides, the underlying mechanism of OR3A4 in CRC development was explored through Western blot and RT-qPCR. RESULTS: OR3A4 expression was significantly higher in CRC tissues than adjacent normal ones. Cell proliferation, migration, and CRC were inhibited after OR3A4 was knocked down in vitro, which were promoted after upregulation of OR3A4. Moreover, OR3A4 could activate the Wnt/ß-catenin pathway, thus influencing phenotypes of CRC cells. CONCLUSIONS: OR3A4 enhances CRC cell proliferation and migration by activating the Wnt/ß-catenin signaling pathway.


Assuntos
Movimento Celular , Neoplasias Colorretais/metabolismo , RNA Longo não Codificante/metabolismo , Via de Sinalização Wnt , beta Catenina/metabolismo , Proliferação de Células , Células Cultivadas , Neoplasias Colorretais/patologia , Humanos , RNA Longo não Codificante/genética
8.
Arch Osteoporos ; 14(1): 15, 2019 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-30719589

RESUMO

We evaluated the efficacy of abaloparatide in women who were at increased risk for fracture, based on CHMP recommended risk thresholds, at the Abaloparatide Comparator Trial In Vertebral Endpoints (ACTIVE) study baseline. Among patients at high risk based on FRAX probabilities, 18 months of abaloparatide significantly decreased risk for all fracture endpoints compared with placebo. PURPOSE: Abaloparatide, a novel anabolic agent for the treatment of postmenopausal osteoporosis, significantly reduced the risk of vertebral and nonvertebral fractures in the ACTIVE study compared with placebo. In this post hoc analysis, we evaluated abaloparatide's efficacy in a subset of women in the study at an increased risk of fracture at baseline, based on the Committee for Medicinal Products for Human Use (CHMP) recommended risk thresholds for inclusion in clinical trials. METHODS: Women with a baseline 10-year risk of major osteoporotic fracture ≥ 10% or hip fracture ≥ 5%, assessed using the FRAX® tool (including femoral neck bone mineral density), were included in the analysis. The proportion with one or more events of new morphometric vertebral fractures was calculated. Event rates for nonvertebral, major osteoporotic, and all clinical fractures were estimated using Kaplan-Meier analysis. RESULTS: Following 18 months of treatment, abaloparatide significantly reduced incident vertebral fractures compared with placebo (relative risk reduction = 91%; 0.5% versus 5.6%; p < 0.001). Abaloparatide treatment was also associated with significantly fewer nonvertebral, major osteoporotic, and clinical fractures compared with placebo: 2.7% versus 5.8%, p = 0.036; 1.3% versus 6.0%, p < 0.001; and 3.5% versus 8.2%, p = 0.006, respectively. The effect of abaloparatide on major osteoporotic fractures (78% reduction) was significantly greater than that seen with teriparatide (23% reduction, p = 0.007). CONCLUSION: In a subset of postmenopausal women at increased risk of fracture as judged by CHMP guidance, abaloparatide significantly decreased the risk of all fracture endpoints compared with placebo.


Assuntos
Conservadores da Densidade Óssea/uso terapêutico , Densidade Óssea/efeitos dos fármacos , Osteoporose Pós-Menopausa/tratamento farmacológico , Fraturas por Osteoporose/prevenção & controle , Proteína Relacionada ao Hormônio Paratireóideo/uso terapêutico , Idoso , Feminino , Fraturas do Quadril/epidemiologia , Fraturas do Quadril/etiologia , Fraturas do Quadril/prevenção & controle , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/complicações , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/etiologia , Pós-Menopausa , Fatores de Risco , Fraturas da Coluna Vertebral/epidemiologia , Fraturas da Coluna Vertebral/etiologia , Fraturas da Coluna Vertebral/prevenção & controle , Resultado do Tratamento
9.
Bone ; 120: 137-140, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30359763

RESUMO

BACKGROUND: Abaloparatide is a 34-amino acid peptide that selectively binds to the RG conformation of the parathyroid hormone receptor type 1. It was developed for the treatment of women with postmenopausal osteoporosis at high risk of fracture. In ACTIVE, an 18-month phase 3 study (NCT01343004), abaloparatide increased bone mineral density (BMD), decreased the risk of vertebral and nonvertebral fractures compared with placebo, and decreased the risk of major osteoporotic fractures compared with placebo and teriparatide. Here, we report a prospective, exploratory BMD responder analysis from ACTIVE. METHODS: Proportions of patients experiencing BMD gains from baseline of >0%, >3%, and >6% at the total hip, femoral neck, and lumbar spine at 6, 12, and 18 months of treatment were compared among the placebo, abaloparatide, and teriparatide groups in ACTIVE. Responders were defined prospectively as patients experiencing BMD gains at all 3 anatomic sites. RESULTS: At months 6, 12, and 18, there were significantly more >3% BMD responders in the abaloparatide group compared with placebo and teriparatide: month 6, 19.1% vs 0.9% for placebo and 6.5% for teriparatide; month 12, 33.2% vs 1.5% and 19.8%; month 18, 44.5% vs 1.9% and 32.0% (P < 0.001 for all comparisons of abaloparatide to placebo and to teriparatide). Findings were similar for the >0% and >6% responder thresholds. CONCLUSIONS: In postmenopausal women with osteoporosis, a significantly greater proportion of patients treated with abaloparatide experienced increases in BMD than did those treated with placebo or teriparatide.


Assuntos
Densidade Óssea/efeitos dos fármacos , Proteína Relacionada ao Hormônio Paratireóideo/farmacologia , Teriparatida/farmacologia , Idoso , Osso e Ossos/efeitos dos fármacos , Feminino , Humanos , Placebos
10.
Zhonghua Er Ke Za Zhi ; 56(10): 769-774, 2018 Oct 02.
Artigo em Chinês | MEDLINE | ID: mdl-30293282

RESUMO

Objective: To explore the clinical and pathological features and mutational types and their relations with WT1 mutation-associated nephropathy (WT1MAN). Methods: The clinical and pathological data and the results of WT1 mutation analysis of the cases from Nanfang Hospital of Southern Medical University, Sun Yat-sen Memorial Hospital and The First Affiliated Hospital of Sun Yat-sen University whom we recruited recently and reported during the last ten years were analyzed. Results: Totally, 20 cases (6 males and 14 females), included 5 newly diagnosed cases, were recruited. (1) Ten children were diagnosed with Denys-Drash syndrome (DDS): The median onset age of proteinuria was 1 year and 7 months. Diffuse mesangial sclerosis (DMS) were revealed in 3 cases, minimal lesions (MCD) in 4 cases, and focal segmental glomerulosclerosis (FSGS) in 1 case; renal pathology was not available in the other 2 cases. Glomerular basement membrane (GBM) thickening was observed in 2 cases. Calcineurin inhibitors (CNIs) were administered in 5 cases, complete remission of proteinuria was observed in 3 cases, partial remission in the other 2 cases. Genetic analysis revealed that six cases had WT1 missense mutation, 3 had nonsense mutation, and 1 had frameshift mutation. (2) Two cases were diagnosed with Frasier syndrome (FS): proteinuria was observed at 1 year and 1 month of age and 1 year and 9 months of age, respectively. FSGS with GBM layering were observed in both cases. They progressed to ESRD at 1 year and 6 months of age and 6 years and 6 months of age, respectively. CNI was tried in 1 case with partial proteinuria remission. Both patients were detected to have WT1 splice mutation. (3) Isolated nephropathy (IN) was observed in 8 cases: three had splice mutation, 5 had missense mutation. Of the 3 patients with splice mutation, one was found to have nephropathy and renal failure at the age of 5 months. The other two cases (1 was FSGS and another MCD), both had GBM layering. CNIs were tried on both of them, one got partial remission with normal renal function at the age of fourteen years, the other one had no response and entered ESRD at the age of 6 years and 9 months. Of the 5 cases with missense mutation, 3 had DMS, 2 of them entered ESRD within 6 months of age, another case had DMS entered ESRD at 9 years of age. One case with FSGS, was treated with CNIs and got complete remission. Conclusions: Slow progression (7/10) nephropathy was observed in DDS patients. Missense mutation (11/20) was the most common type of WT1 variants, followed by splice mutation (5/20) in this group of patients. Early onset nephropathy (4/5), rapid progression (4/5) and GBM layering (4/4) wereobserved in patients with splice mutation. CNI was effective in reducing or even eliminating proteinuria in WT1 MAN patients (8/9).


Assuntos
Síndrome de Denys-Drash , Nefropatias , Síndrome Nefrótica , Proteínas WT1 , Criança , Síndrome de Denys-Drash/genética , Progressão da Doença , Feminino , Humanos , Nefropatias/genética , Masculino , Mutação de Sentido Incorreto , Síndrome Nefrótica/genética , Resultado do Tratamento , Proteínas WT1/genética
11.
Acta Physiol (Oxf) ; 224(2): e13075, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29660255

RESUMO

AIM: Experimental simulation of near-future ocean acidification (OA) has been demonstrated to affect growth and development of echinoderm larval stages through energy allocation towards ion and pH compensatory processes. To date, it remains largely unknown how major pH regulatory systems and their energetics are affected by trans-generational exposure to near-future acidification levels. METHODS: Here, we used the common sea star Asterias rubens in a reciprocal transplant experiment comprising different combinations of OA scenarios, to study trans-generational plasticity using morphological and physiological endpoints. RESULTS: Acclimation of adults to pHT 7.2 (pCO2 3500 µatm) led to reductions in feeding rates, gonad weight and fecundity. No effects were evident at moderate acidification levels (pHT 7.4; pCO2 2000 µatm). Parental pre-acclimation to pHT 7.2 for 85 days reduced developmental rates even when larvae were raised under moderate and high pH conditions, whereas pre-acclimation to pHT 7.4 did not alter offspring performance. Microelectrode measurements and pharmacological inhibitor studies carried out on larval stages demonstrated that maintenance of alkaline gastric pH represents a substantial energy sink under acidified conditions that may contribute up to 30% to the total energy budget. CONCLUSION: Parental pre-acclimation to acidification levels that are beyond the pH that is encountered by this population in its natural habitat (eg, pHT 7.2) negatively affected larval size and development, potentially through reduced energy transfer. Maintenance of alkaline gastric pH and reductions in maternal energy reserves probably constitute the main factors for a reduced juvenile recruitment of this marine keystone species under simulated OA.


Assuntos
Aclimatação/fisiologia , Asterias/fisiologia , Trato Gastrointestinal/fisiologia , Homeostase/fisiologia , Água do Mar/química , Animais , Mudança Climática , Trato Gastrointestinal/química , Humanos , Concentração de Íons de Hidrogênio , Larva
12.
Neoplasma ; 65(1): 81-88, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29322792

RESUMO

Oncogenic Kras with loss of heterozygosity (LOH) is frequently detected in various tumours. However, the exact function and mechanism by which KrasG12D-LOH operates remain unclear. Therefore, the current study investigated the effect of KrasG12D-LOH on the malignant phenotype of pancreatic ductal adenocarcinoma (PDAC) cells. Our investigation revealed that KrasG12D-LOH is associated with increased proliferation, invasion and reduced apoptosis in PDAC cells. The results also exhibited enhanced glycolytic phenotype of KrasG12D-LOH PDAC cells. Hyperactive mTOR plays a significant role in the initiation and maintenance of tumors. To investigate the correlation between KrasG12D-LOH and mTOR, the mTOR signaling pathway was detected by western blot analysis. We found that KrasG12D-LOH up-regulated Akt, AMPK, REDD1 and mTOR in PDAC cells. In summary, our results demonstrated that KrasG12D-LOH promotes oncogenic Kras-induced PDAC by regulating energy metabolism and mTOR signaling pathway. These data may provide novel therapeutic perspectives for PDAC.


Assuntos
Carcinoma Ductal Pancreático/metabolismo , Perda de Heterozigosidade , Neoplasias Pancreáticas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Metabolismo Energético , Humanos
13.
J Opt Soc Am A Opt Image Sci Vis ; 34(9): 1476-1480, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29036149

RESUMO

Light-emitting diodes (LEDs) are widely employed in industrial applications and scientific research. However, spectral distortions will occur due to the broadening effects of the spectrometer when an LED spectrum is obtained with a spectrometer. In this paper, a novel approach is put forward to correct bandwidth for an LED spectrum based on a Levenberg-Marquardt algorithm and He-Zheng model. We compare estimation errors of different LED spectra by using the proposed method along with the Richardson-Lucy method and differential operator approach. The experimental results show that the effect of the proposed approach is better than that of the other two methods.

14.
Rev Sci Instrum ; 88(12): 125109, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29289218

RESUMO

A new miniature panoramic diamond anvil cell (mini-pDAC) as well as a unique gas membrane-driven mechanism is developed and implemented to measure electronic, magnetic, vibrational, and thermodynamic properties of materials using the nuclear resonant inelastic X-ray scattering (NRIXS) and the synchrotron Mössbauer spectroscopy (SMS) simultaneously at high pressure (over Mbar) and low temperature (T < 10 K). The gas membrane system allows in situ pressure tuning of the mini-pDAC at low temperature. The mini-pDAC fits into a specially designed compact liquid helium flow cryostat system to achieve low temperatures, where liquid helium flows through the holder of the mini-pDAC to cool the sample more efficiently. The system has achieved sample temperatures as low as 9 K. Using the membrane, sample pressures of up to 1.4 Mbar have been generated from this mini-pDAC. The instrument has been routinely used at 3-ID, Advanced Photon Source, for NRIXS and SMS studies. The same instrument can easily be used for other X-ray techniques, such as X-ray radial diffraction, X-ray Raman scattering, X-ray emission spectroscopy, and X-ray inelastic scattering under high pressure and low temperature. In this paper, technical details of the mini-pDAC, membrane engaging mechanism, and the cryostat system are described, and some experimental results are discussed.

15.
Phys Chem Chem Phys ; 18(27): 17805-9, 2016 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-27328161

RESUMO

The vibrational dynamics of a newly synthesized tetrastannoxane was characterized with a combination of experimental (Raman, IR and tin-based nuclear resonance vibrational spectroscopy) and computational (DFT/B3LYP) methods, with an emphasis on the vibrations of the tin sites. The cytotoxic activity revealed a significant regression selectively against the human pancreatic cell lines.


Assuntos
Benzaldeídos/química , Compostos Organometálicos/química , Neoplasias Pancreáticas/química , Neoplasias Pancreáticas/metabolismo , Estanho/química , Linhagem Celular Tumoral , Humanos , Conformação Molecular , Teoria Quântica , Espectrofotometria Infravermelho , Vibração
16.
Genet Mol Res ; 14(4): 15365-75, 2015 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-26634502

RESUMO

The development of diabetic peripheral neuropathy (DPN) is always followed by changes in vascular endothelial cells that are related to the reactivity of the homocysteine (Hcy) sulfhydryl group. In this meta-analysis, we investigated the association of Hcy with the pathogenesis and progression of DPN. We screened the Embase, Ovid, PubMed, Web of Science, Wangfang, and China National Knowledge Infrastructure databases. All analyses were performed by using the STATA software, version 12.0 (StataCorp, College Station, TX, USA) and the Comprehensive Meta-analysis 2.0 software (Biostatic Inc., Englewood, NJ, USA). The standardized mean difference (SMD) and 95% confidence interval (95%CI) were further calculated. The electronic literature search identified six articles that included 603 patients with DPN and 687 healthy controls. The pooled SMD of those six studies revealed that increased serum levels of Hcy may be correlated with DPN (SMD = 1.23, 95%CI: 1.09-1.36, P < 0.001). Subgroup analysis according to ethnicity indicated that high serum Hcy levels might be an important risk factor for DPN in both Asian and Caucasian populations (Asians: SMD = 0.62, 95%CI: 0.45-0.79, P < 0.001; Caucasians: SMD = 2.32, 95%CI: 2.10-2.55, P < 0.001; respectively). Elevated serum levels of Hcy indicate the risk of development of DPN in patients, suggesting that Hcy levels could be used as a marker for new therapeutic approaches to DPN.


Assuntos
Diabetes Mellitus/sangue , Neuropatias Diabéticas/sangue , Homocisteína/sangue , Doenças do Sistema Nervoso Periférico/sangue , Idoso , Povo Asiático , Biomarcadores/sangue , Estudos de Casos e Controles , China , Progressão da Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , População Branca
17.
J Chem Phys ; 143(16): 164508, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26520528

RESUMO

The pressure-induced amorphization and subsequent recrystallization of SnI4 have been investigated using first principles molecular dynamics calculations together with high-pressure (119)Sn nuclear resonant inelastic x-ray scattering measurements. Above ∼8 GPa, we observe a transformation from an ambient crystalline phase to an intermediate crystal structure and a subsequent recrystallization into a cubic phase at ∼64 GPa. The crystalline-to-amorphous transition was identified on the basis of elastic compatibility criteria. The measured tin vibrational density of states shows large amplitude librations of SnI4 under ambient conditions. Although high pressure structures of SnI4 were thought to be determined by random packing of equal-sized spheres, we detected electron charge transfer in each phase. This charge transfer results in a crystal structure packing determined by larger than expected iodine atoms.

18.
J Synchrotron Radiat ; 22(5): 1155-62, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26289266

RESUMO

A high-resolution silicon monochromator suitable for 21.541 keV synchrotron radiation is presented that produces a bandwidth of 0.27 meV. The operating energy corresponds to a nuclear transition in (151)Eu. The first-of-its-kind, fully cryogenic design achieves an energy-alignment stability of 0.017 meV r.m.s. per day, or a 100-fold improvement over other meV-monochromators, and can tolerate higher X-ray power loads than room-temperature designs of comparable resolution. This offers the potential for significantly more accurate measurements of lattice excitation energies using nuclear resonant vibrational spectroscopy if combined with accurate energy calibration using, for example, high-speed Doppler shifting. The design of the monochromator along with its performance and impact on transmitted beam properties are presented.

19.
Cell Mol Biol (Noisy-le-grand) ; 61(2): 18-25, 2015 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-26025397

RESUMO

Human umbilical cord mesenchymal stem cells (hUCMSCs) have important functions on the expansion of hematopoietic stem cells (HSCs) through providing the essential microenvironment for hematopoiesis. In order to test whether CD44 on hUCMSCs could have a key function for the ability of hUCMSCs to expand human HSCs, the soluble anti—CD44 antibody was added to the co—cultures of hUCMSCs and cord blood (CB) CD34+ cells, which blocked the ability of hUCMSCs to expand CB CD34+ cells significantly. Long—term culture initiating cell (LTC—IC) assay revealed that the ability of multipotent differentiation of CB CD34+ cells co—cultured with CD44 knockdown hUCMSCs could only retain lasting at most for 5 weeks in vitro. In vivo assay, based on non—obese diabetic/severe combined immunodeficient disease (NOD/SCID) mice, revealed that the hematopoietic reconstitution potential of CB CD34+ cells co—cultured with CD44 knockdown hUCMSCs is significantly reduced. The hematopoietic supporting ability of hUCMSCs in vivo and in vitro is reduced upon the knockdown of CD44. CD44 has important functions on the ability of hUCMSCs to expand human HSCs in the cell— extrinsic control.


Assuntos
Hematopoese/genética , Células-Tronco Hematopoéticas/citologia , Receptores de Hialuronatos/genética , Células-Tronco Mesenquimais/citologia , Animais , Antígenos CD34/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Microambiente Celular/fisiologia , Sangue Fetal/citologia , Fase G1/fisiologia , Hematopoese/fisiologia , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Interferência de RNA , RNA Interferente Pequeno , Fase S/fisiologia , Cordão Umbilical/citologia
20.
Phys Rev Lett ; 114(5): 057202, 2015 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-25699465

RESUMO

By combination of two independent approaches, nuclear resonant inelastic x-ray scattering and first-principles calculations in the framework of density functional theory, we demonstrate significant changes in the element-resolved vibrational density of states across the first-order transition from the ferromagnetic low temperature to the paramagnetic high temperature phase of LaFe(13-x)Si(x). These changes originate from the itinerant electron metamagnetism associated with Fe and lead to a pronounced magneto-elastic softening despite the large volume decrease at the transition. The increase in lattice entropy associated with the Fe subsystem is significant and contributes cooperatively with the magnetic and electronic entropy changes to the excellent magneto- and barocaloric properties.

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