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1.
Nat Commun ; 15(1): 4851, 2024 Jun 06.
Artículo en Inglés | MEDLINE | ID: mdl-38844818

RESUMEN

The manipulation of spin textures by spin currents is of fundamental and technological interest. A particularly interesting system is the 2D van der Waals ferromagnet Fe3GeTe2, in which Néel-type skyrmions have recently been observed. The origin of these chiral spin textures is of considerable interest. Recently, it was proposed that these derive from defects in the structure that lower the symmetry and allow for a bulk vector Dzyaloshinsky-Moriya interaction. Here, we demonstrate current-induced domain wall motion in Fe3GeTe2 flakes, in which the maximum domain wall velocity is an order of magnitude higher than those reported in previous studies. In heterostructures with Pt or W layers on top of the Fe3GeTe2 flakes, domain walls can be moved via a combination of spin transfer and spin-orbit torques. The competition between these torques leads to a change in the direction of domain wall motion with increasing magnitude of the injected current.

2.
Cureus ; 16(4): e58448, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38765417

RESUMEN

INTRODUCTION: Needlestick injuries (NSIs) represent a significant occupational health risk in healthcare settings. These injuries, caused by contaminated sharps such as needles, vials, and scalpel blades, can lead to percutaneous exposure to infectious materials. Despite the severity of NSIs, they often go unreported, highlighting a critical gap in occupational safety protocols. AIMS: This study aimed to investigate the occurrence of NSIs among healthcare workers (HCWs) by sex, profession, and working areas. It also sought to explore the underlying reasons for these injuries and the factors contributing to their underreporting. METHODOLOGY: Adhering to the RECORD guidelines (Reporting of studies Conducted using Observational Routinely Collected Data), this record-based study involved a retrospective analysis of reported NSIs. Data were collected from voluntary reports by HCWs who experienced NSIs or exposure to potentially infectious materials such as blood and body fluids. Statistical analysis was conducted using IBM SPSS Statistics for Windows, Version 16 (Released 2007; IBM Corp., Armonk, New York) and Microsoft Excel 2010 (Microsoft Corporation, Redmond, Washington). RESULTS: Data from 142 participants indicated a higher proportion of females experiencing NSIs compared to males, with rates of 57.7% pre-COVID and 60.6% during COVID. There were notable shifts in NSI rates across professions, with increases observed among staff nurses and ward attendants/helpers. Analysis of injury circumstances revealed a decrease in sampling procedure-related injuries but an increase during intravenous procedures and biomedical waste segregation. Injuries occurring on the right-hand index finger decreased from 52.1% pre-COVID to 31% during COVID, while those on the left-hand index finger increased from 19.7% pre-COVID to 39.4% during COVID. Statistically significant associations were found between the injury site and the place of occurrence (p=0.021). Healthcare professionals commonly cleansed the site with disinfectants and used personal protective equipment (PPE) kits, with increased PPE usage noted during the COVID-19 pandemic. These findings emphasize the evolving dynamics of NSIs among HCWs and underscore the importance of tailored preventive measures during pandemics.

3.
ACS Nano ; 2024 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-38315563

RESUMEN

The family of two-dimensional (2D) van der Waals (vdW) materials provides a playground for tuning structural and magnetic interactions to create a wide variety of spin textures. Of particular interest is the ferromagnetic compound Fe5GeTe2 that we show displays a range of complex spin textures as well as complex crystal structures. Here, using a high-brailliance laboratory X-ray source, we show that the majority (1 × 1) Fe5GeTe2 (FGT5) phase exhibits a structure that was previously considered as being centrosymmetric but rather lacks inversion symmetry. In addition, FGT5 exhibits a minority phase that exhibits a long-range ordered (√3 × âˆš3)-R30° superstructure. This superstructure is highly interesting in that it is innately 2D without any lattice periodicity perpendicular to the vdW layers, and furthermore, the superstructure is a result of ordered Te vacancies in one of the topmost layers of the FGT5 sheets rather than being a result of vertical Fe ordering as earlier suggested. We show, from direct real-space magnetic imaging, evidence for three distinct magnetic ground states in lamellae of FGT5 that are stabilized with increasing lamella thickness, namely, a multidomain state, a stripe phase, and an unusual fractal state. In the stripe phase we also observe unconventional type-I and type-II bubbles where the spin texture in the central region of the bubbles is nonuniform, unlike conventional bubbles. In addition, we find a bobber or a cocoon-like spin texture in thick (∼170 µm) FGT5 that emerges from the fractal state in the presence of a magnetic field. Among all the 2D vdW magnets we have thus demonstrated that FGT5 hosts perhaps the richest variety of magnetic phases that, thereby, make it a highly interesting platform for the subtle tuning of magnetic interactions.

4.
Ann Med ; 55(2): 2291554, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38079515

RESUMEN

Background: Tuberculosis (TB) and malnutrition are major global health problems, with multidrug-resistant (MDR) TB complicating international efforts. The role of vitamin D in susceptibility to and as an adjunctive treatment for TB is being studied extensively, although no study has included MDR-TB patients in context to dietary profile with vitamin D levels and sunlight exposure.Objective: This study aimed to estimate vitamin D serum levels and examine their association with dietary intake of vitamin D and sun exposure in patients with MDR-TB.Methods: North Indian participants were enrolled in three groups: MDR-TB, drug-susceptible pulmonary TB (DS-PTB), and healthy controls. All consenting participants underwent the estimation of macro- and micronutrient intake and sunlight exposure using structured questionnaires. Serum biochemistry, including 25-hydroxyvitamin D and calcium levels, was measured, and the correlation between variables was determined.Results: 747 participants were enrolled. Significant differences among the three groups were found in mean serum 25-hydroxyvitamin D levels, body mass index, macronutrient intake, dietary vitamin D and calcium content, and sun exposure index (SEI). All except sun exposure (SEI was highest in DS-PTB patients) were found to follow the trend: MDR-TB < DS-PTB < healthy controls. The mean serum vitamin D levels of all groups were deficient and correlated positively with dietary intake and SEI.Conclusion: In this study's we found significant association of serum vitamin D concentrations, dietary intake and sunlight exposure in MDR-TB, DS-PTB patients and healthy controls. Dietary intake may be more important than sun exposure in determining serum levels. However, the significance of this finding is uncertain. Further studies are required to confirm the association, direction, and potential for vitamin D supplementation to treat or prevent MDR-TB infection.


Asunto(s)
Tuberculosis Resistente a Múltiples Medicamentos , Tuberculosis Pulmonar , Deficiencia de Vitamina D , Humanos , Deficiencia de Vitamina D/tratamiento farmacológico , Deficiencia de Vitamina D/epidemiología , Calcio/uso terapéutico , Vitamina D , Dieta , Vitaminas , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico , Tuberculosis Resistente a Múltiples Medicamentos/epidemiología , Tuberculosis Resistente a Múltiples Medicamentos/complicaciones , Luz Solar , Tuberculosis Pulmonar/tratamiento farmacológico , Tuberculosis Pulmonar/epidemiología
5.
Sci Adv ; 9(28): eadg7269, 2023 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-37436976

RESUMEN

Materials with Kagome nets are of particular importance for their potential combination of strong correlation, exotic magnetism, and electronic topology. KV3Sb5 was discovered to be a layered topological metal with a Kagome net of vanadium. Here, we fabricated Josephson Junctions of K1-xV3Sb5 and induced superconductivity over long junction lengths. Through magnetoresistance and current versus phase measurements, we observed a magnetic field sweeping direction-dependent magnetoresistance and an anisotropic interference pattern with a Fraunhofer pattern for in-plane magnetic field but a suppression of critical current for out-of-plane magnetic field. These results indicate an anisotropic internal magnetic field in K1-xV3Sb5 that influences the superconducting coupling in the junction, possibly giving rise to spin-triplet superconductivity. In addition, the observation of long-lived fast oscillations shows evidence of spatially localized conducting channels arising from edge states. These observations pave the way for studying unconventional superconductivity and Josephson device based on Kagome metals with electron correlation and topology.

6.
Biochim Biophys Acta Mol Basis Dis ; 1869(7): 166806, 2023 10.
Artículo en Inglés | MEDLINE | ID: mdl-37437748

RESUMEN

Autophagy maintains cellular homeostasis and plays a crucial role in managing pathological conditions including ischemic myocardial injury leading to heart failure (HF). Despite treatments, no intervention can replace lost cardiomyocytes. Stem cell therapy offers potential for post-myocardial infarction repair but struggles with poor cell retention due to immune rejection. In the search for effective therapies, stem cell-derived extracellular vesicles (EVs), especially exosomes, have emerged as promising tools. These tiny bioactive molecule carriers play vital roles in intercellular communication and tissue engineering. They offer numerous therapeutic benefits including modulating immune responses, promoting tissue repair, and boosting angiogenesis. Additionally, biomaterials provide a conducive 3D microenvironment for cell, exosome, and biomolecule delivery, and enhance heart muscle strength, making it a comprehensive cardiac repair strategy. In this regard, the current review delves into the intricate application of extracellular vesicles (EVs) and biomaterials for managing autophagy in the heart muscle during cardiac injury. Central to our investigation is the exploration of how these elements interact within the context of cardiac repair and regeneration. Additionally, this review also casts light on the formidable challenges that plague this field, such as the issues of safety, efficacy, controlled delivery, and acceptance of these therapeutic strategies for effective clinical translation. Addressing these challenges is crucial for unlocking the full therapeutic potential of EV and biomaterial-based therapies and ensuring their successful translation from bench to bedside.


Asunto(s)
Exosomas , Lesiones Cardíacas , Humanos , Materiales Biocompatibles/uso terapéutico , Miocitos Cardíacos , Células Madre , Autofagia
7.
Indian J Endocrinol Metab ; 27(2): 145-153, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37292078

RESUMEN

Aims: Phase I of the Prevalence of Gestational Diabetes Mellitus in Rural Dehradun (PGDRD) project estimates hyperglycemia in pregnancy (HIP) prevalence and identifies gaps in the utilization of community-related services in rural areas of the Dehradun district (western Uttarakhand); a state where notably no prior population-based study has ever been conducted despite being an Empowered Action Group state for more than two decades. Methods: Using a multistage random sampling technique, 1,223 pregnant women locally registered in the rural field practice area of a block were identified. Those requiring HIP screening were subjected to a 2-h 75 g oral glucose tolerance test during the house visit irrespective of their period-of-gestation and last meal timings, diagnosed using the Diabetes in Pregnancy Study Group India (DIPSI) criterion (when indicated). Data were collected by personal interviews using a pretested data collection tool. Statistical Package for Social Sciences version 20.0 was used for analysis. Results: The overall HIP prevalence recorded was 9.7% (95% CI: 8.1-11.5%); the majority (95.8%) were GDM followed by overt DIP (4.2%). Less than 1% of the subjects (0.7%) self-reported pre-GDM. Despite this burden, more than three-fourths were never screened for HIP in their pregnancy. Of those tested, the majority availed secondary healthcare facilities. Few even had to bear expenses in private with a very handful being tested free-of-cost by ANM in the community; findings that altogether sharply contrast to those recommended by national protocols. Conclusion: Despite the high HIP burden, beneficiaries are unable to utilize community-related universal screening protocols as desired.

8.
J Midlife Health ; 14(4): 237-245, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-38504740

RESUMEN

Background: Middle age is a link between adulthood and old age, which requires special attention. During middle age among females, changes like menopause occur, which is responsible for causing various physical, vasomotor, psychological, and social changes, which may affect overall well-being and positive mental health status. Hence, the present study has been planned to assess the prevalence of menopausal symptoms among middle-aged females. Materials and Methods: The present study was a cross-sectional study carried out in rural and urban areas of district Dehradun among 400 females. A stratified systematic random sampling technique method was used. All the females fulfilling the inclusion criteria and aged 40-60 years were included in the study. The Menopause-Specific Quality of Life (MENQOL) questionnaire was used to assess the prevalence of menopausal symptoms. Results: A total of 400 women were recruited in the study, 200 from rural and urban areas each. The mean age of the total study participants was 50.00 ± 0.32 years. Among 400 middle-aged women, 189 were premenopausal and 211 were postmenopausal. The frequencies of occurrence of menopausal symptoms were explored in 189 premenopausal and 211 postmenopausal women. The mean age of premenopausal women was 44.21 ± 2.35 and postmenopausal was 54.39 ± 4.21. Females experienced varying grades of MENQOL symptoms. Conclusions: It was found that majority of the females' quality of life were found to be affected with different grades of menopausal symptoms. With increasing age, symptoms also increase and are significantly high among postmenopausal women.

9.
Sci Rep ; 12(1): 21496, 2022 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-36513699

RESUMEN

Poly(ADP-ribose) polymerase-1 (PARP1), a fundamental DNA repair enzyme, is known to regulate ß cell death, replication, and insulin secretion. PARP1 knockout (KO) mice are resistant to diabetes, while PARP1 overactivation contributes to ß cell death. Additionally, PARP1 inhibition (PARPi) improves diabetes complications in patients with type-2 diabetes. Despite these beneficial effects, the use of PARP1 modulating agents in diabetes treatment is largely neglected, primarily due to the poorly studied mechanistic action of PARP1 catalytic function in human ß cell development. In the present study, we evaluated PARP1 regulatory action in human ß cell differentiation using the human pancreatic progenitor cell line, PANC-1. We surveyed islet census and histology from PARP1 wild-type versus KO mice pancreas in a head-to-head comparison with PARP1 regulatory action for in-vitro ß cell differentiation following either PARP1 depletion or its pharmacological inhibition in PANC-1-differentiated islet cells. shRNA mediated PARP1 depleted (SiP) and shRNA control (U6) PANC-1 cells were differentiated into islet-like clusters using established protocols. We observed complete abrogation of new ß cell formation with absolute PARP1 depletion while its inhibition using the potent inhibitor, PJ34, promoted the endocrine ß cell differentiation and maturation. Immunohistochemistry and immunoblotting for key endocrine differentiation players along with ß cell maturation markers highlighted the potential regulatory action of PARP1 and augmented ß cell differentiation due to direct interaction of unmodified PARP1 protein elicited p38 MAPK phosphorylation and Neurogenin-3 (Ngn3) re-activation. In summary, our study suggests that PARP1 is required for the proper development and differentiation of human islets. Selective inhibition with PARPi can be an advantage in pushing more insulin-producing cells under pathological conditions and delivers a potential for pilot clinical testing for ß cell replacement cell therapies for diabetes.


Asunto(s)
Islotes Pancreáticos , Poli(ADP-Ribosa) Polimerasa-1 , Animales , Humanos , Ratones , Diferenciación Celular , Islotes Pancreáticos/metabolismo , Ratones Noqueados , Poli(ADP-Ribosa) Polimerasa-1/metabolismo , ARN Interferente Pequeño
10.
J Educ Health Promot ; 11: 321, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36568011

RESUMEN

BACKGROUND: The preeminent mental health conditions, namely social phobia and depression among adolescents, usually remain incognito. The transition period from childhood to adulthood makes adolescents more liable for low amour-propre, loneliness, and even increases the suicidal tendencies among them. To burgeon the knowledge regarding social phobia and depression among adolescents, the present study was put forward with the objective to assess the prevalence of social anxiety disorders (social phobia) and depression among adolescents. MATERIALS AND METHODS: A cross-sectional study was conducted for 2 months on 600 students aged 10-19 years belonging to classes VIII-XII of government and private schools in the Dehradun district recruited through multistage random sampling technique. A pre-tested semi-structured questionnaire having sociodemographic details, validated self-administered tools, Social Phobia Inventory tool, and Kutchers Adolescent Depression Scale (Cronbach's alpha: 0.77 and 0.79) were used. Statistical package for social sciences, version 23 was used for data analysis. Chi-square test, Fisher exact test, and Pearson correlation analysis were used for analysis. RESULTS: Prevalence of social phobia was found to be 37% among school-going adolescents. Further, 23.7% of the study participants had mild social phobia, while moderate and severe phobia was seen among 11.5% and 2.3%, respectively. Females had more moderate and severe social phobia than males. Adolescents of government schools had more moderate affective distress and somatic distress as compared to adolescents of private schools. CONCLUSION: Social phobia and depression among school-going adolescents are on the upsurge. The present study shows that social phobia and depression have a strong correlation among themselves, which needs to be addressed as expeditiously as possible. Coping strategies and social skill therapy and programs are pressing priorities for the fulgent future of adolescents.

11.
ACS Appl Mater Interfaces ; 14(40): 45096-45109, 2022 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-36171536

RESUMEN

The development of superior functional enzyme mimics (nanozymes) is essential for practical applications, including point-of-care diagnostics, biotechnological applications, biofuels, and environmental remediation. Nanozymes with the ability to control their catalytic activity in response to external fuels offer functionally valuable platforms mimicking nonequilibrium systems in nature. Herein, we fabricated a supramolecular coordination bonding-based dynamic vesicle that exhibits multienzymatic activity. The supramolecular nanozyme shows effective laccase-like catalytic activity with a KM value better than the native enzyme and higher stability in harsh conditions. Besides, the nanostructure demonstrates an efficient peroxidase-like activity with NADH peroxidase-like properties. Generation of luminescence from luminol and oxidation of dopamine are efficiently catalyzed by the nanozyme with high sensitivity, which is useful for point-of-care detections. Notably, the active nanozyme exhibits dynamic laccase-mimetic activity in response to pH variation, which has never been explored before. While a neutral/high pH leads to the self-assembly, a low pH disintegrates the assembled nanostructures and consequently turns off the nanozyme activity. Altogether, the self-assembled Cu2+-based vesicular nanostructure presents a pH-fueled dissipative system demonstrating effective temporally controlled multienzymatic activity.


Asunto(s)
Lacasa , Nanoestructuras , Biocombustibles , Catálisis , Dopamina , Luminol , Nanoestructuras/química , Peroxidasas
12.
Stem Cell Res ; 64: 102921, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36152425

RESUMEN

In this study we report reprogramming and generation of a new human induced pluripotent stem cell line UOMi009_A, which was generated from a 64 year old male patient with childhood onset Hypophosphatasia (HPP). The patient has compound heterozygous mutations in the ALPL gene (c.571G>A (p.Glu191Lys) and c.1001G>A (p.Gly334Asp)) which were confirmed in the UOMi009_A line. This line was well characterized and will help in our future assessment of HPP disease pathophysiology and drug screening.


Asunto(s)
Hipofosfatasia , Células Madre Pluripotentes Inducidas , Masculino , Humanos , Niño , Persona de Mediana Edad , Hipofosfatasia/genética , Células Madre Pluripotentes Inducidas/metabolismo , Fosfatasa Alcalina/genética , Fosfatasa Alcalina/metabolismo , Línea Celular
13.
Stem Cell Res ; 64: 102891, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35964540

RESUMEN

A new induced pluripotent stem cell (iPSC) line namely UOMi008-A was generated from a patient having a childhood onset of Hypophosphatasia (HPP). This patient has compound heterozygous mutations c.571G > A (p.Glu191Lys) and c.1001G > A (p.Gly334Asp) in the ALPL gene respectively. This iPSC line will be used for in vitro disease modeling, which will aid in delineating the underlying molecular mechanism involved in disease pathogenesis and provide plausible new therapeutic directions.


Asunto(s)
Hipofosfatasia , Células Madre Pluripotentes Inducidas , Humanos , Niño , Hipofosfatasia/genética , Hipofosfatasia/patología , Células Madre Pluripotentes Inducidas/patología , Fosfatasa Alcalina/genética , Mutación/genética , Línea Celular
14.
Stem Cell Res ; 63: 102839, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35700635

RESUMEN

Hypophosphatasia (HPP) is a rare, inherited, metabolic, genetic disorder, which arises due to loss of function mutation in the alkaline phosphatase (ALPL) gene. We have created a new induced pluripotent stem cell line (UOMi007-A) from peripheral blood mononuclear cells (PBMCs) of an 18 yr. old male patient having compound heterozygous mutations in the ALPL gene c.571G>A (p.Glu191Lys) and c.1001G>A (p.Gly334Asp) respectively. This line can be used for exploration into the molecular mechanisms of disease pathophysiology, screen new potential drugs and design cell therapy studies that can be personalized or used for future patients.


Asunto(s)
Hipofosfatasia , Células Madre Pluripotentes Inducidas , Fosfatasa Alcalina/genética , Línea Celular , Humanos , Hipofosfatasia/genética , Leucocitos Mononucleares , Masculino , Mutación/genética
15.
World J Microbiol Biotechnol ; 38(8): 139, 2022 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-35705749

RESUMEN

Tremendous benefits have been derived from the use of fungicides but excessive use of chemical fungicides not only posing threat to human and animal life but also contaminates the prevailing environment. Damage by pathogenic fungi alone causes significant damage to crops like maize, rice, wheat, soybeans, and potatoes. Therefore, it becomes imperative that these diseases are checked and controlled, for which chemical pesticides are being sprayed on plants extensively. Considering the devastating damage and toxicity, the global focus has taken a drift from synthetic chemicals to nature-friendly biological control agents. The present study focuses on the use of biological control agents particularly Trichoderma in sugarcane during Pokkah boeng infection. In the present experiment, twenty promising Trichoderma strains were evaluated for plant growth promotion, lytic enzymes, and physiological and biocontrol activity. Out of the twenty, four potential Trichoderma strains were assessed in the pot experiment viz. T. harzianum strain T28, T41 and T49 and T. aureoviride strain T38. The T. harzianum (T28) showed efficient plant growth-promoting traits as it produced IAA (20.67 µg/ml), phosphorus solubilization (18.57 µg/ml), and cell wall degrading enzymes such as chitinase (24.98 µg/ml) and ß-glucanase (29.98 µg/ml). The interference of biocontrol agent T. harzianum (T28) controlled the disease by 73.55%. Apart from this, the inoculation of Trichoderma (T28) enhanced growth attributes including germination percentage (26.61%), mean tiller number (8.28 tiller/pot), individual cane length (241.5 cm), single cane weight (1.13 kg) and the number of milleable canes (6.00 cane/pot). Improvements in physiological activities at different growth stages of the sugarcane crop were observed based on the photosynthetically active radiation (PAR) on the leaf surface, transpiration rate, stomatal conductance, and photosynthetic rate. Further, improvement in juice quality parameters was also observed as it recorded the highest 0brix, sucrose, and commercial cane sugar by 21.26%, 19.28%, and 13.50%, respectively, by applying T. harzianum strain T28. Thus, results proved that T. harzianum strain T28 may be an effective eco-friendly biocontrol tool for managing Pokkah boeng disease in sugarcane. This is the first report of the biocontrol potential of Trichoderma spp. against Fusarium proliferatum causing Pokkah boeng disease in sugarcane.


Asunto(s)
Quitinasas , Fungicidas Industriales , Saccharum , Trichoderma , Agentes de Control Biológico/farmacología , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control , Saccharum/microbiología
16.
Chem Commun (Camb) ; 58(56): 7833-7836, 2022 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-35748501

RESUMEN

Reactive oxygen species (ROS)-responsive near infrared (NIR) fluorogenic prodrug DCI-ROS is developed for the self-immolative release of diclofenac (DCF) with turn-on fluorescence. The non-toxic prodrug exhibited turn-on red fluorescence with endogenous ROS in cancer cells and inhibited COX-2 expression in the inflammation-induced macrophage cells. The prodrug strategy thus would be helpful for the controlled fluorogenic delivery of DCF for inflammatory diseases.


Asunto(s)
Profármacos , Antiinflamatorios no Esteroideos/farmacología , Diclofenaco/farmacología , Liberación de Fármacos , Fluorescencia , Profármacos/farmacología , Especies Reactivas de Oxígeno/metabolismo
17.
Sci Adv ; 8(24): eabo5930, 2022 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-35704587

RESUMEN

The current-induced spin-orbit torque switching of ferromagnets has had huge impact in spintronics. However, short spin-diffusion lengths limit the thickness of switchable ferromagnetic layers, thereby limiting their thermal stability. Here, we report a previously unobserved seeded spin-orbit torque (SSOT) by which current can set the magnetic states of even thick layers of the chiral kagome antiferromagnet Mn3Sn. The mechanism involves setting the orientation of the antiferromagnetic domains in a thin region at the interface with spin currents arising from an adjacent heavy metal while also heating the layer above its magnetic ordering temperature. This interface region seeds the resulting spin texture of the entire layer as it cools down and, thereby, overcomes the thickness limitation of conventional spin-orbit torques. SSOT switching in Mn3Sn can be extended beyond chiral antiferromagnets to diverse magnetic systems and provides a path toward the development of highly efficient, high-speed, and thermally stable spintronic devices.

18.
Sci Adv ; 8(14): eabl4370, 2022 04 08.
Artículo en Inglés | MEDLINE | ID: mdl-35394834

RESUMEN

A "Leap-of-Faith" approach is used to treat patients with previously unknown ultrarare pathogenic mutations, often based on evidence from patients having dissimilar but more prevalent mutations. This uncertainty reflects the need to develop personalized prescreening platforms for these patients to assess drug efficacy before considering clinical trial enrollment. In this study, we report an 18-year-old patient with ultrarare Leigh-like syndrome. This patient had previously participated in two clinical trials with unfavorable responses. We established an induced pluripotent stem cell (iPSC)-based platform for this patient, and assessed the efficacy of a panel of drugs. The iPSC platform validated the safety and efficacy of the screened drugs. The efficacy of three of the screened drugs was also investigated in the patient. After 3 years of treatment, the drugs were effective in shifting the metabolic profile of this patient toward healthy control. Therefore, this personalized iPSC-based platform can act as a prescreening tool to help in decision-making with respect to patient's participation in future clinical trials.


Asunto(s)
Células Madre Pluripotentes Inducidas , Adolescente , Humanos , Células Madre Pluripotentes Inducidas/metabolismo
19.
Mol Cell Biochem ; 477(6): 1681-1695, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35235124

RESUMEN

A significantly high percentage of hospitalized COVID-19 patients with diabetes mellitus (DM) had severe conditions and were admitted to ICU. In this review, we have delineated the plausible molecular mechanisms that could explain why there are increased clinical complications in patients with DM that become critically ill when infected with SARS-CoV2. RNA viruses have been classically implicated in manifestation of new onset diabetes. SARS-CoV2 infection through cytokine storm leads to elevated levels of pro-inflammatory cytokines creating an imbalance in the functioning of T helper cells affecting multiple organs. Inflammation and Th1/Th2 cell imbalance along with Th17 have been associated with DM, which can exacerbate SARS-CoV2 infection severity. ACE-2-Ang-(1-7)-Mas axis positively modulates ß-cell and cardiac tissue function and survival. However, ACE-2 receptors dock SARS-CoV2, which internalize and deplete ACE-2 and activate Renin-angiotensin system (RAS) pathway. This induces inflammation promoting insulin resistance that has positive effect on RAS pathway, causes ß-cell dysfunction, promotes inflammation and increases the risk of cardiovascular complications. Further, hyperglycemic state could upregulate ACE-2 receptors for viral infection thereby increasing the severity of the diabetic condition. SARS-CoV2 infection in diabetic patients with heart conditions are linked to worse outcomes. SARS-CoV2 can directly affect cardiac tissue or inflammatory response during diabetic condition and worsen the underlying heart conditions.


Asunto(s)
COVID-19 , Enfermedades Cardiovasculares , Diabetes Mellitus , Enzima Convertidora de Angiotensina 2 , COVID-19/complicaciones , Supervivencia Celular , Síndrome de Liberación de Citoquinas , Humanos , ARN Viral , SARS-CoV-2
20.
Adv Mater ; 34(11): e2108637, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35048455

RESUMEN

There is considerable interest in van der Waals (vdW) materials as potential hosts for chiral skyrmionic spin textures. Of particular interest is the ferromagnetic, metallic compound Fe3 GeTe2 (FGT), which has a comparatively high Curie temperature (150-220 K). Several recent studies have reported the observation of chiral Néel skyrmions in this compound, which is inconsistent with its presumed centrosymmetric structure. Here the observation of Néel type skyrmions in single crystals of FGT via Lorentz transmission electron microscopy (LTEM) is reported. It is shown from detailed X-ray diffraction structure analysis that FGT lacks an inversion symmetry as a result of an asymmetric distribution of Fe vacancies. This vacancy-induced breaking of the inversion symmetry of this compound is a surprising and novel observation and is a prerequisite for a Dzyaloshinskii-Moriya vector exchange interaction which accounts for the chiral Néel skyrmion phase. This phenomenon is likely to be common to many 2D vdW materials and suggests a path to the preparation of many such acentric compounds. Furthermore, it is found that the skyrmion size in FGT is strongly dependent on its thickness: the skyrmion size increases from ≈100 to ≈750 nm as the thickness of the lamella is increased from ≈90 nm to ≈2 µm. This extreme size tunability is a feature common to many low symmetry ferro- and ferri-magnetic compounds.

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