Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 40
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Small ; : e2405051, 2024 Aug 02.
Artículo en Inglés | MEDLINE | ID: mdl-39092657

RESUMEN

Metal-organic frameworks (MOFs)-related Cu materials are promising candidates for promoting electrochemical CO2 reduction to produce valuable chemical feedstocks. However, many MOF materials inevitable undergo reconstruction under reduction conditions; therefore, exploiting the restructuring of MOF materials is of importance for the rational design of high-performance catalyst targeting multi-carbon products (C2). Herein, a facile solvent process is choosed to fabricate HKUST-1 with an anionic framework (a-HKUST-1) and utilize it as a pre-catalyst for alkaline CO2RR. The a-HKUST-1 catalyst can be electrochemically reduced into Cu with significant structural reconstruction under operating reaction conditions. The anionic HKUST-1 derived Cu catalyst (aHD-Cu) delivers a FEC2H4 of 56% and FEC2 of ≈80% at -150 mA cm-2 in alkaline electrolyte. The resulting aHD-Cu catalyst has a high electrochemically active surface area and low coordinated sites. In situ Raman spectroscopy indicates that the aHD-Cu surface displays higher coverage of *CO intermediates, which favors the production of hydrocarbons.

2.
Phys Chem Chem Phys ; 25(3): 2342-2348, 2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36597962

RESUMEN

Among many modulation methods, strain engineering is often chosen for nanomaterials to produce tunable band gaps continuously. Inspired by the recently reported two-dimensional material PC3, we explore the tuning of strain on the spin-dependent transport properties of PC3 nanoribbons using the first-principle approach. Surprisingly, strain regulation achieves uninterrupted completely dual-spin polarization over a wide energy range near EF. Analysis reveals that the peculiar transmission spectra arise from the interesting evolution of the band structure, in which strain induces bands to shift and broaden/flatten. This results in triggering the transition of PC3NRs from bandgap-tunable bipolar magnetic semiconductors to spin-gapless semiconductors to ferromagnetic metals or half-metal magnets. Their unique performance demonstrates great potential in spintronics, and our study is expected to provide ideas and theoretical support for the design and application of novel PC3-based spintronic devices in the future.

3.
Phys Chem Chem Phys ; 25(4): 3544, 2023 Jan 27.
Artículo en Inglés | MEDLINE | ID: mdl-36636943

RESUMEN

Correction for 'Rich magnetic phase transitions and completely dual-spin polarization of zigzag PC3 nanoribbons under uniaxial strain' by Hui-Min Ni et al., Phys. Chem. Chem. Phys., 2023, https://doi.org/10.1039/d2cp05066h.

4.
BMC Cardiovasc Disord ; 23(1): 354, 2023 07 17.
Artículo en Inglés | MEDLINE | ID: mdl-37460957

RESUMEN

BACKGROUND: We aim to determine predictors of inadequate left ventricular mass index (LVMi) regression at mid-term after transcatheter aortic valve replacement (TAVR), including the potential role of epicardial adipose tissue (EAT). METHODS: We retrospectively reviewed patients with both echocardiographic assessments and multi-slice computed tomography (MSCT) obtained one year after TAVR. The change of LVMi, the volume and the average CT attenuation of EAT from baseline to one-year follow-up was calculated. Patients were divided into two groups by the percentage change of LVMi at a cut-off of 15%. RESULTS: A total of 152 patients were included with a median age of 74 years (interquartile range [IQR] 69-78 years) and 56.6% being male. LVMi decreased (P < 0.0001) while EAT volume increased and the average CT attenuation decreased (both P < 0.0001) at one year. Baseline atrial fibrillation (P = 0.042), mitral regurgitation ≥ mild (P = 0.006), aortic regurgitation (AR) > mild (P = 0.001) and the change in the average CT attenuation of EAT (P = 0.026) were different between the decrease of LVMi ≥ 15% and < 15%. AR > mild at baseline was the only statistically significant predictor of a decrease of LVMi < 15% at one year (OR 0.33, 95% CI: 0.13 to 0.84, P = 0.021) in multivariate regression. CONCLUSIONS: Concomitant more-than-mild AR might predict better left ventricular reverse remodeling regression after TAVR.


Asunto(s)
Insuficiencia de la Válvula Aórtica , Estenosis de la Válvula Aórtica , Reemplazo de la Válvula Aórtica Transcatéter , Humanos , Masculino , Anciano , Femenino , Reemplazo de la Válvula Aórtica Transcatéter/efectos adversos , Insuficiencia de la Válvula Aórtica/diagnóstico por imagen , Insuficiencia de la Válvula Aórtica/etiología , Insuficiencia de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/cirugía , Estenosis de la Válvula Aórtica/complicaciones , Estudios Retrospectivos , Función Ventricular Izquierda , Resultado del Tratamiento , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/cirugía , Índice de Severidad de la Enfermedad , Remodelación Ventricular
5.
J Chem Phys ; 158(20)2023 May 28.
Artículo en Inglés | MEDLINE | ID: mdl-37212402

RESUMEN

The unique edge states of the zigzag ß-SiC7 nanoribbons aroused our attention, and therefore, based on first-principles calculations, we investigated their spin-dependent electronic transport properties by constructing controllable defects to modulate these special edge states. Interestingly, by introducing rectangular edge defects in the SiSi and SiC edge-terminated systems, not only the spin-unpolarized is successfully converted to completely spin-polarized, but also the direction of polarization can be switched, thus enabling a dual spin filter. The analyses further reveal that the two transmission channels with opposite spins are spatially separated and that the transmission eigenstates are highly concentrated at the relative edges. The specific edge defect introduced only suppresses the transmission channel at the same edge but reserves the transmission channel at the other edge. In addition, for the CSi and CC edge-terminated systems, an additional spin-down band exists due to spin splitting in the spin-up band at EF, so that besides the original spatially separated two spin-opposite channels, an extra spin channel is distributed at the upper edge, resulting in unidirectional fully spin-polarized transport. The peculiar spatially separated edge states and excellent spin filtering properties could open up further possibilities for ß-SiC7-based electronic devices in spintronics applications.

6.
Phys Chem Chem Phys ; 24(41): 25656-25662, 2022 Oct 27.
Artículo en Inglés | MEDLINE | ID: mdl-36255329

RESUMEN

Compared with traditional magnetic approaches, electrical modulation of spin-polarized current can greatly reduce the energy consumption and scale of nanodevices and improve their operating speed, which has become a promising research field in spintronics. Motivated by the latest reported novel two-dimensional material ß-SiC7, we employ first-principles calculations to investigate its spin-dependent electron transport with diverse edge configurations. By introducing a gate voltage, the three-terminal device can not only switch between spin-unpolarized and fully spin-polarized states, but also easily change the polarization direction, behaving as an excellent electrically modulated reversible dual-spin filter. Surprisingly, an arbitrary proportion of spin-up and spin-down electron numbers is achieved, enabling precise control of spin polarization. Analysis reveals that it is attributed to the peculiar transmission spectrum, where two broad peaks with opposite spins are located around the Fermi level and respond differently to gate voltage. They belong to the spatially separated edge states originating from the p orbitals of the edge atoms. This feature is robust to different edge configurations of ß-SiC7 nanoribbons, indicating that this may be an intrinsic property of such systems, showing great potential for applications.

7.
Opt Express ; 29(21): 33642-33664, 2021 Oct 11.
Artículo en Inglés | MEDLINE | ID: mdl-34809173

RESUMEN

Aiming to determine the scattered estimation of complex and electrically large targets coated with the uniaxial electric anisotropic medium (UEAM) from a distributed excitation source, the demanding study is simplified by constructing the physical optics (PO) architecture which consists of three aspects, the discrete facet modeling, the tangent plane approximation, and the scattering of an infinite PEC plate coated with the UEAM based on point-source excitation, including the electric and magnetic dipole. We depict the outer surface of an electrically large scatterer as the constitution of countless tiny triangular facets. From the tangent plane approximation employed in the PO method, the scattered fields of any discretized facet induced by the equivalent electromagnetic currents (EECs) can be further evaluated as the surface fields of an infinite UEAM-coated PEC slab. Therefore, the rigorous solution of the dyadic Green's function (DGFs) for an infinite anisotropic-medium-coated PEC plate under point-source incidence is computed first. Moreover, characterizing the ray propagation process of the plane wave spectrum, the asymptotic technique of the saddle point is employed to obtain the scattered ray field in the spatial domain. Finally, the total scattered fields are obtained by the field superposition of the overall illuminated facets under point-source excitation. Compared with the reference solution, the proposed method is validated, and the simulation results of the representative shapes coated with the UEAM layer from a point source are presented.

8.
Asia Pac J Clin Nutr ; 30(1): 7-14, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33787035

RESUMEN

BACKGROUND AND OBJECTIVES: Little is known about nutritional status in patients with hepatocellular carcinoma (HCC) after multiple rounds of transarterial chemoembolization (TACE). We established a comprehensive nutritional index (CNI) and evaluated its prognostic value for overall survival (OS) and time to progression (TTP). METHODS AND STUDY DESIGN: HCC patients (N=282) who underwent multiple TACE treatments were enrolled. CNI was established by principal component analysis based on body mass index, usual body weight percentage, hemoglobin, total lymphocyte count, and albumin; the cutoff value was determined by receiver operating characteristic curve and Youden index analysis. The correlation between CNI and treatment-related complications was analyzed with Spearman's method. The Kaplan-Meier method with log-rank test and Cox proportional hazards model were used to compare the prognostic values of CNI, prognostic nutritional index (PNI), and nutrition risk index (NRI) for OS and TTP. RESULTS: Nutritional status declined after repeated TACE (p<0.001). CNI (cutoff= 0.251) varied according to albumin-bilirubin grade, tumor size, and number of TACE treatments (p<0.001 or 0.025) and was negatively correlated with rate of serious complications (r=-0.185, p=0.002). Patients with low CNI had shorter OS (p=0.014) and TTP (p=0.007); high CNI predicted longer OS (hazard ratio [HR], 0.72; 95% confidence interval [CI]: 0.52-1.00, p=0.048) and TTP (HR, 0.69; 95% CI: 0.50-0.94, p=0.019). Post-treatment PNI and NRI were unrelated to prognosis (p>0.05). CONCLUSIONS: HCC patients have poor nutritional status after multiple TACE treatments, which predicts shorter OS and TTP. The prognostic performance of CNI is superior to those of PNI and NRI.


Asunto(s)
Carcinoma Hepatocelular , Quimioembolización Terapéutica , Neoplasias Hepáticas , Carcinoma Hepatocelular/terapia , Humanos , Neoplasias Hepáticas/terapia , Evaluación Nutricional , Pronóstico , Estudios Retrospectivos , Resultado del Tratamiento
9.
Appl Opt ; 58(4): 1158-1163, 2019 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-30874167

RESUMEN

We report on a non-contact method for external right-angle measurement using two autocollimators. A precise mathematical model is deduced to evaluate and deduct the measuring error. The values measured with our method are very coincident compared with the results measured by a ZYGO interferometer. The measuring accuracy is superior to 0.1 arcsec for the right-angle errors within 3.0 arcsec and becomes 0.4 arcsec for the extended right-angle errors within 8.0 arcsec. This method can be widely used in situations for external right-angle measurement, such as angle measurement for the body of torsion balance and test mass in spaceborne laser interferometry.

10.
Phys Chem Chem Phys ; 20(45): 28759-28766, 2018 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-30417191

RESUMEN

The two-dimensional material C3N has a honeycomb structure similar to graphene, but its heterogeneity of carbon and nitrogen elements makes it multifunctional. By performing a first-principles study, we find that edge morphology induces interesting electronic transport properties in step-like heterojunction devices composed of width-variable zigzag C3N nanoribbons. As long as the right part has an edge of all-carbon morphology, negative differential resistance and rectification effects will occur. If both edges are not of all-carbon morphology due to the presence of N atoms, a forward-conducting and reverse-blocking rectifier diode behavior will appear. These phenomena originate from the peculiar electronic structure of the zigzag C3N nanoribbons. The number of energy bands crossing the Fermi level gradually decreases from 2 to 0 as the number of all-carbon edges decreases, realizing a transition from metal to semiconductor. The band gap determines the cut-off region at low bias and the presence of an interface barrier causes the cut-off state to continue under high reverse bias. Diverse edge morphologies, simple cutting methods and rich electronic transport properties make C3N materials competitive in nanodevice applications.

12.
Mol Cell Biochem ; 395(1-2): 155-65, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24952481

RESUMEN

MicroRNAs are a family of small, non-coding RNAs that regulate gene expression in a sequence-specific manner. Estrogen-related receptor α (ERRα) is an orphan nuclear receptor which plays an important role in adipocyte differentiation. Our previous Solexa sequencing results indicated a high expression of miR-125a in adult pig backfat. In this study, we predicated and experimentally validated ERRα as a target of miR-125a. To explore the role of miR-125a in porcine preadipocytes differentiation, miRNA agomir and antagomir were used to perform miR-125a overexpression or knockdown, respectively. Our results showed that overexpression of miR-125a could dramatically reduce the mRNA expression of adipogenic markers PPARγ, LPL, and aP2, as well as its target gene ERRα. Western blotting showed the protein level of aP2 and ERRα was also significantly down-regulated. The overexpression of miR-125a also led to a notable reduction in lipid accumulation which was detected by Oil Red O staining. In contrast, we observed promoted differentiation of porcine preadipocytes upon miR-125a inhibition. In conclusion, we verified miR-125a inhibits porcine preadipocytes differentiation through targeting ERRα for the first time, which may provide new insights in pork quality improvement and obesity control.


Asunto(s)
Adipocitos/fisiología , MicroARNs/genética , MicroARNs/metabolismo , Receptores de Estrógenos/genética , Sus scrofa/fisiología , Adipocitos/citología , Animales , Diferenciación Celular , Células Cultivadas , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Modelos Biológicos , Receptores de Estrógenos/metabolismo , Receptor Relacionado con Estrógeno ERRalfa
13.
Nat Commun ; 15(1): 168, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38168065

RESUMEN

Endoplasmic reticulum (ER)-mitochondria contacts are critical for the regulation of lipid transport, synthesis, and metabolism. However, the molecular mechanism and physiological function of endoplasmic reticulum-mitochondrial contacts remain unclear. Here, we show that Mic19, a key subunit of MICOS (mitochondrial contact site and cristae organizing system) complex, regulates ER-mitochondria contacts by the EMC2-SLC25A46-Mic19 axis. Mic19 liver specific knockout (LKO) leads to the reduction of ER-mitochondrial contacts, mitochondrial lipid metabolism disorder, disorganization of mitochondrial cristae and mitochondrial unfolded protein stress response in mouse hepatocytes, impairing liver mitochondrial fatty acid ß-oxidation and lipid metabolism, which may spontaneously trigger nonalcoholic steatohepatitis (NASH) and liver fibrosis in mice. Whereas, the re-expression of Mic19 in Mic19 LKO hepatocytes blocks the development of liver disease in mice. In addition, Mic19 overexpression suppresses MCD-induced fatty liver disease. Thus, our findings uncover the EMC2-SLC25A46-Mic19 axis as a pathway regulating ER-mitochondria contacts, and reveal that impairment of ER-mitochondria contacts may be a mechanism associated with the development of NASH and liver fibrosis.


Asunto(s)
Metabolismo de los Lípidos , Enfermedad del Hígado Graso no Alcohólico , Ratones , Animales , Metabolismo de los Lípidos/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Estrés del Retículo Endoplásmico , Hígado/metabolismo , Mitocondrias/metabolismo , Cirrosis Hepática/patología , Retículo Endoplásmico/metabolismo
14.
Yao Xue Xue Bao ; 48(11): 1705-9, 2013 Nov.
Artículo en Zh | MEDLINE | ID: mdl-24475709

RESUMEN

To screen the harmful substance 5-hydroxymethyl furfural content in commercially available traditional Chinese medicine injection which are commonly used, and to preliminarily evaluate the quality of these injections, 5-hydroxymethyl furfural was taken as an index. The contents of 5-hydroxymethyl furfural in 56 samples which consist of 23 kinds of traditional Chinese medicine injections and glucose injection were determined using LC-MS/MS, and 5-hydroxymethyl furfural was detected in 52 of these samples. The minimal content was 0.0038 microg x L(-1) and the maximum content was 1420 microg x mL(-1). The contents of 5-hydroxymethyl furfural were significantly different in traditional Chinese medicine injection which came from different kinds, manufacturers or batches. The results showed the quality difference of commercially available traditional Chinese medicine injection is significant taking 5-hydroxymethyl furfural content as assessment index. More attention should be paid to the safety of 5-hydroxymethyl furfural in traditional Chinese medicine injection, and unified limitation standard should be set to improve medication safety of traditional Chinese medicine injection.


Asunto(s)
Medicamentos Herbarios Chinos/química , Furaldehído/análogos & derivados , Plantas Medicinales/química , Cromatografía Liquida , Combinación de Medicamentos , Medicamentos Herbarios Chinos/administración & dosificación , Eleutherococcus/química , Furaldehído/análisis , Glucosa/administración & dosificación , Glucosa/química , Inyecciones , Medicina Tradicional China , Extractos Vegetales/administración & dosificación , Extractos Vegetales/química , Espectrometría de Masas en Tándem
15.
Front Physiol ; 14: 999736, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37234409

RESUMEN

Objective: The present study aimed to use bedside ultrasound to evaluate the effects of metoclopramide on gastric motility in patients being treated for trauma in the emergency department. Methods: Fifty patients underwent an ultrasound immediately after attending the emergency department of Zhang Zhou Hospital due to trauma. The patients were randomly divided into two groups: a metoclopramide group (group M, n = 25) and a normal saline group (group S, n = 25). The cross-sectional area (CSA) of the gastric antrum was measured at 0, 30, 60, 90, and 120 min (T = time). The gastric emptying rate (GER, GER=-AareaTn/AareaTn-30-1×100), GER/min (GER divided by the corresponding interval time), gastric content properties, Perlas grade at different time points, T120 gastric volume (GV), and GV per unit of body weight (GV/W) were evaluated. The risk of vomiting, reflux/aspiration, and type of anesthetic treatment were also evaluated. Results: The differences between the two groups in the CSA of the gastric antrum at each time point were statistically significant (p < 0.001). The CSAs of the gastric antrum in group M were lower than those in group S, and the greatest difference between the two groups occurred at T30 (p < 0.001). The differences between the two groups in GER and GER/min were also statistically significant (p < 0.001); those differences in group M were higher than those in group S, and the greatest differences between the two groups occurred at T30 (p < 0.001). There were no obvious change trends in the properties of the gastric contents and the Perlas grades in either group, and the differences between the two groups were not statistically significant (p = 0.97). The differences between the two groups in the GV and GV/W at T120 were statistically significant (p < 0.001), as was the risk of reflux and aspiration at T120 (p < 0.001). Conclusion: When metoclopramide was used in satiated emergency trauma patients, it accelerated gastric emptying within 30 min and reduced the risk of accidental reflux. However, a normal gastric emptying level was not achieved, which can be attributed to the delaying effect of trauma on gastric emptying.

16.
J Clin Med ; 12(15)2023 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-37568469

RESUMEN

The snare-assisted technique has been described to facilitate transcatheter aortic valve replacement (TAVR) delivery system advancement in complex aortic anatomies. However, the evidence is limited to case reports. To evaluate the safety profile of the snare-facilitated approach and its impact on self-expanding (SE) TAVR outcomes, we collected consecutive patients who underwent transfemoral SE-TAVR for aortic stenosis, using propensity score matching (PSM) separately in tricuspid and type-0 and type-1 bicuspid aortic valve morphology between the snare and non-snare groups. In 766 patients, despite the snare group having significantly larger annulus angulation and maximal ascending aortic diameter, both groups achieved comparable 30-day device success rates, regardless of first-generation or new-generation valve use. After PSM, the snare group had a significantly lower new permanent pacemaker implantation rate among 193 type-0 patients (3.3% vs. 18.3%, p = 0.01). The ipsilateral group used new-generation valves less frequently (23.0% vs. 75.4%, p < 0.001), but there were no significant inter-group differences in procedure-related events, except for a lower incidence of PVL ≥ mild in the ipsilateral group (14.9% vs. 32.3%, p = 0.01). In conclusion, the snare-assisted technique appears useful in SE-TAVR with angulated aortic root anatomy, and the benefits were comparable between ipsilateral and contralateral snare techniques.

17.
World J Clin Cases ; 10(6): 1998-2006, 2022 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-35317165

RESUMEN

BACKGROUND: Mutations that occur in the ABCB4 gene, which encodes multidrug-resistant protein 3, underlie the occurrence of progressive familial intrahepatic cholestasis type 3 (PFIC3). Clinical signs of intrahepatic cholestasis due to gene mutations typically first appear during infancy or childhood. Reports of PFIC3 occurring in adults are rare. CASE SUMMARY: This is a case study of a 32-year-old infertile female Chinese patient with a 15-year history of recurrent abnormal liver function. Her primary clinical signs were elevated levels of alkaline phosphatase and γ-glutamyl transpeptidase. Other possible reasons for liver dysfunction were eliminated in this patient, resulting in a diagnosis of PFIC3. The diagnosis was confirmed using gene detection and histological analyses. Assessments using genetic sequencing analysis indicated the presence of two novel heterozygous mutations in the ABCB4 gene, namely, a 2950C>T; p.A984V mutation (exon 24) and a 667A>G; p.I223V mutation (exon 7). After receiving ursodeoxycholic acid (UDCA) treatment, the patient's liver function indices improved, and she successfully became pregnant by in vitro fertilization. However, the patient developed intrahepatic cholestasis of pregnancy in the first trimester. Fortunately, treatment with UDCA was safe and effective. CONCLUSION: These novel ABCB4 heterozygous mutations have a variety of clinical phenotypes. Continued follow-up is essential for a comprehensive understanding of PFIC3.

18.
Nanoscale ; 14(16): 6118-6125, 2022 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-35388866

RESUMEN

Sodium-ion batteries (SIBs) have attracted great attention owing to their low cost and inherent safety. High-performance anode materials for SIBs should possess intrinsically metallic characteristic and be composed of non-toxic, earth abundant, and lightweight elements. We predict a two-dimensional Mg material (named magnesene) to be an excellent anode material, which can meet these design requirements. It is demonstrated to be stable in terms of the cohesive energy, phonon spectrum, ab initio molecular dynamics simulation, and elastic constants. The magnesene monolayer exhibits good SIB performances, including a high storage capacity of 551.3 mA h g-1, low diffusion energy barrier (0.16-0.19 eV), low open-circuit voltage (0.71-0.82 V), and small volume change (4.7%). Moreover, graphene or h-BN on top of magnesene could serve as a protective cover to preserve the performances of pristine magnesene, such as metallicity, strong Na adsorption capability, and fast ionic mobility. These intriguing theoretical findings make magnesene a promising anode material for SIBs.

19.
Front Chem ; 10: 1103704, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36569959

RESUMEN

Two-dimensional antiferromagnetic semiconductors have triggered significant attention due to their unique physical properties and broad application. Based on first-principles calculations, a novel two-dimensional (2D) antiferromagnetic material MnSi2N4 monolayer is predicted. The calculation results show that the two-dimensional MnSi2N4 prefers an antiferromagnetic state with a small band gap of 0.26 eV. MnSi2N4 has strong antiferromagnetic coupling which can be effectively tuned under strain. Interestingly, the MnSi2N4 monolayer exhibits a half-metallic ferromagnetic properties under an external magnetic field, in which the spin-up electronic state displays a metallic property, while the spin-down electronic state exhibits a semiconducting characteristic. Therefore, 100% spin polarization can be achieved. Two-dimensional MnSi2N4 monolayer has potential application in the field of high-density information storage and spintronic devices.

20.
Fertil Steril ; 118(5): 906-914, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36175209

RESUMEN

OBJECTIVE: To evaluate the current evidence of pregnancy outcomes among couples with recurrent pregnancy loss (RPL) with abnormal karyotypes vs. those with normal karyotypes and among couples with RPL and abnormal karyotypes after receiving expectant management vs. preimplantation genetic diagnosis (PGD). DESIGN: Systematic review and meta-analysis. SETTING: Academic medical centers. PATIENT(S): Pregnancy outcomes in 6,301 couples with RPL who conceived without medical intervention in 11 studies were analyzed. However, only 2 studies addressed the outcomes of couples with RPL and abnormal karyotypes after expectant management (75 cases) vs. PGD (50 cases). INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The pregnancy outcomes in couples with RPL with abnormal and normal karyotypes across included studies were evaluated. RESULT(S): Compared with those with a normal karyotype, a significantly lower first pregnancy live birth rate (LBR) was found in couples with RPL with abnormal karyotypes (58.5% vs. 71.9%; odds ratio [OR], 0.55; 95% confidence interval [CI], 0.46-0.65; I2 =27%). A markedly decreased first pregnancy LBR was found in couples with a translocation (52.9% vs. 72.4%; OR, 0.44; 95% CI, 0.31-0.61; I2 =33%) but not in couples with an inversion. However, the differences in accumulated LBR (81.4% vs. 74.8%; OR, 0.96; 95% CI, 0.90-1.03; I2 = 0) were nonsignificant, whereas the miscarriage rate was distinctly higher in couples with RPL and abnormal karyotypes (53.0% vs. 34.7%; OR, 2.21; 95% CI, 1.69-2.89; I2 = 0). Compared with those who chose expectant management, differences in accumulated LBR were nonsignificant (60% vs. 68%; OR, 0.55; 95% CI, 0.11-2.62; I2 =71%), whereas the miscarriage rate (24% vs. 65.3%; OR, 0.15; 95% CI, 0.04-0.51; I2 = 45) was markedly low in couples with RPL and abnormal karyotypes who chose PGD. CONCLUSION(S): Couples with RPL and abnormal karyotypes had a higher miscarriage rate than couples with normal karyotypes but achieved a noninferior accumulated LBR through multiple conception attempts. In couples with RPL and abnormal karyotypes, PGD treatment did not increase the accumulated LBR but markedly reduced miscarriage rate compared with expectant management.


Asunto(s)
Aborto Habitual , Diagnóstico Preimplantación , Embarazo , Femenino , Humanos , Resultado del Embarazo/epidemiología , Aborto Habitual/diagnóstico , Aborto Habitual/genética , Cariotipo Anormal , Padres
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA