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1.
Cureus ; 16(6): e62971, 2024 Jun.
Article in English | MEDLINE | ID: mdl-39044877

ABSTRACT

BACKGROUND:  Intestinal obstruction in neonates remains a critical medical emergency in the field of pediatric surgery. Clinical conditions often experience a sudden deterioration in their appearance. Multiple factors contribute to unfavorable clinical outcomes in underdeveloped nations. The study was conducted to identify the etiology, management, and outcomes of neonatal intestinal obstruction at a specialized medical facility. METHODS:  This retrospective study included 168 newborns who had to be operated on in the neonatal intensive care unit between 2021 and 2023 due to intestinal obstruction. The clinical and demographic characteristics of the infants, final diagnosis, surgical complications, and mortality rate were documented. In addition, the relationship between risk factors such as birth weight, gestational age, length of surgery, and postoperative problems was evaluated. RESULTS:  The majority of neonatal intestinal obstruction occurred within seven days of birth, with 8-15 days being the second most common. Most babies were born at full term (53.57%) and weighed 2 kg or more (75%). In newborns in our region, duodenal, ileal, jejunal, and colonic atresias were found to be the most common causes of neonatal intestinal obstruction that requires surgery. The study detected 45 postoperative problems, 26.79% of the total. Out of 168 patients, twelve (7.14%) had septicemia, seven (4.17%) had anastomotic leak, seven (4.17%) had aspiration pneumonitis, and two (1.19%) needed re-exploration. Overall mortality was 10.12%, with 17 patients dying. Moreover, 119 patients (70.83%) survived without issues, while 32 (19.05%) survived with complications. CONCLUSION:  Our findings emphasize the significance of promptly diagnosing, intervening, and implementing suitable management approaches to enhance outcomes for newborns with intestinal obstruction. Furthermore, it highlights valuable perspectives for healthcare professionals in enhancing care for this specific group of patients.

2.
Nat Commun ; 15(1): 4998, 2024 Jun 12.
Article in English | MEDLINE | ID: mdl-38866830

ABSTRACT

Collective spin-wave excitations, magnons, are promising quasi-particles for next-generation spintronics devices, including platforms for information transfer. In a quantum Hall ferromagnets, detection of these charge-neutral excitations relies on the conversion of magnons into electrical signals in the form of excess electrons and holes, but if the excess electron and holes are equal, detecting an electrical signal is challenging. In this work, we overcome this shortcoming by measuring the electrical noise generated by magnons. We use the symmetry-broken quantum Hall ferromagnet of the zeroth Landau level in graphene to launch magnons. Absorption of these magnons creates excess noise above the Zeeman energy and remains finite even when the average electrical signal is zero. Moreover, we formulate a theoretical model in which the noise is produced by equilibration between edge channels and propagating magnons. Our model also allows us to pinpoint the regime of ballistic magnon transport in our device.

3.
J Cell Sci ; 137(11)2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38757366

ABSTRACT

Nesprin proteins, which are components of the linker of nucleoskeleton and cytoskeleton (LINC) complex, are located within the nuclear envelope and play prominent roles in nuclear architecture. For example, LINC complex proteins interact with both chromatin and the cytoskeleton. Here, we report that the Drosophila Nesprin MSP300 has an additional function in autophagy within larval body wall muscles. RNAi-mediated MSP300 knockdown in larval body wall muscles resulted in defects in the contractile apparatus, muscle degeneration and defective autophagy. In particular, MSP300 knockdown caused accumulation of cytoplasmic aggregates that contained poly-ubiquitylated cargo, as well as the autophagy receptor ref(2)P (the fly homolog of p62 or SQSTM) and Atg8a. Furthermore, MSP300 knockdown larvae expressing an mCherry-GFP-tagged Atg8a transgene exhibited aberrant persistence of the GFP signal within these aggregates, indicating failure of autophagosome maturation. These autophagy deficits were similar to those exhibited by loss of the endoplasmic reticulum (ER) fusion protein Atlastin (Atl), raising the possibility that Atl and MSP300 might function in the same pathway. In support of this possibility, we found that a GFP-tagged MSP300 protein trap exhibited extensive localization to the ER. Alteration of ER-directed MSP300 might abrogate important cytoskeletal contacts necessary for autophagosome completion.


Subject(s)
Autophagy , Drosophila Proteins , Proteostasis , Animals , Drosophila Proteins/metabolism , Drosophila Proteins/genetics , Drosophila melanogaster/metabolism , Drosophila melanogaster/genetics , Endoplasmic Reticulum/metabolism , Muscles/metabolism , Larva/metabolism , Larva/genetics , Microfilament Proteins , Muscle Proteins
4.
Phys Rev Lett ; 132(9): 096301, 2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38489611

ABSTRACT

This Letter presents a nonlocal study on the electric-field-tunable edge transport in h-BN-encapsulated dual-gated Bernal-stacked (ABA) trilayer graphene across various displacement fields (D) and temperatures (T). Our measurements revealed that the nonlocal resistance (R_{NL}) surpassed the expected classical Ohmic contribution by a factor of at least 2 orders of magnitude. Through scaling analysis, we found that the nonlocal resistance scales linearly with the local resistance (R_{L}) only when the D exceeds a critical value of ∼0.2 V/nm. Additionally, we observed that the scaling exponent remains constant at unity for temperatures below the bulk-band gap energy threshold (T<25 K). Further, the value of R_{NL} decreases in a linear fashion as the channel length (L) increases. These experimental findings provide evidence for edge-mediated charge transport in ABA trilayer graphene under the influence of a finite displacement field. Furthermore, our theoretical calculations support these results by demonstrating the emergence of dispersive edge modes within the bulk-band gap energy range when a sufficient displacement field is applied.

5.
PLoS One ; 19(1): e0291477, 2024.
Article in English | MEDLINE | ID: mdl-38166124

ABSTRACT

Several lines of evidence demonstrate that increased neuronal excitability can enhance proteomic stress. For example, epilepsy can enhance the proteomic stress caused by the expression of certain aggregation-prone proteins implicated in neurodegeneration. However, unanswered questions remain concerning the mechanisms by which increased neuronal excitability accomplishes this enhancement. Here we test whether increasing neuronal excitability at a particular identified glutamatergic synapse, the Drosophila larval neuromuscular junction, can enhance the proteomic stress caused by mutations in the ER fusion/GTPase gene atlastin (atl). It was previously shown that larval muscle from the atl2 null mutant is defective in autophagy and accumulates protein aggregates containing ubiquitin (poly-UB aggregates). To determine if increased neuronal excitability might enhance the increased proteomic stress caused by atl2, we activated the TrpA1-encoded excitability channel within neurons. We found that TrpA1 activation had no effect on poly-UB aggregate accumulation in wildtype muscle, but significantly increased poly-UB aggregate number in atl2 muscle. Previous work has shown that atl loss from either neuron or muscle increases muscle poly-UB aggregate number. We found that neuronal TrpA1 activation enhanced poly-UB aggregate number when atl was removed from muscle, but not from neuron. Neuronal TrpA1 activation enhanced other phenotypes conferred by muscle atl loss, such as decreased pupal size and decreased viability. Taken together, these results indicate that the proteomic stress caused by muscle atl loss is enhanced by increasing neuronal excitability.


Subject(s)
Motor Neurons , Proteomics , Animals , Motor Neurons/metabolism , Muscles/metabolism , Proteins/metabolism , Drosophila/metabolism , Autophagy
6.
Autophagy ; 20(1): 131-150, 2024 01.
Article in English | MEDLINE | ID: mdl-37649246

ABSTRACT

ABBREVIATIONS: atl atlastin; ALR autophagic lysosome reformation; ER endoplasmic reticulum; GFP green fluorescent protein; HSP hereditary spastic paraplegia; Lamp1 lysosomal associated membrane protein 1 PolyUB polyubiquitin; RFP red fluorescent protein; spin spinster; mTor mechanistic Target of rapamycin; VCP valosin containing protein.


Subject(s)
Autophagy , Drosophila , Animals , Autophagy/physiology , Lysosomes/metabolism , Muscles , TOR Serine-Threonine Kinases/metabolism
7.
PLoS One ; 17(12): e0278598, 2022.
Article in English | MEDLINE | ID: mdl-36516171

ABSTRACT

The ɸC31 integrase system is widely used in Drosophila melanogaster to allow transgene targeting to specific loci. Over the years, flies bearing any of more than 100 attP docking sites have been constructed. One popular docking site, termed attP40, is located close to the Nesprin-1 orthologue msp-300 and lies upstream of certain msp-300 isoforms and within the first intron of others. Here we show that attP40 causes larval muscle nuclear clustering, which is a phenotype also conferred by msp-300 mutations. We also show that flies bearing insertions within attP40 can exhibit decreased msp-300 transcript levels in third instar larvae. Finally, chromosomes carrying certain "transgenic RNAi project" (TRiP) insertions into attP40 can confer pupal or adult inviability or infertility, or dominant nuclear clustering effects in certain genetic backgrounds. These phenotypes do not require transcription from the insertions within attP40. These results demonstrate that attP40 and insertion derivatives act as msp-300 insertional mutations. These findings should be considered when interpreting data from attP40-bearing flies.


Subject(s)
Chromosomes , Drosophila melanogaster , Animals , Drosophila melanogaster/genetics , Mutagenesis, Insertional , Phenotype , Larva
8.
Nat Commun ; 13(1): 5185, 2022 Sep 03.
Article in English | MEDLINE | ID: mdl-36057650

ABSTRACT

To determine the topological quantum numbers of fractional quantum Hall (FQH) states hosting counter-propagating (CP) downstream (Nd) and upstream (Nu) edge modes, it is pivotal to study quantized transport both in the presence and absence of edge mode equilibration. While reaching the non-equilibrated regime is challenging for charge transport, we target here the thermal Hall conductance GQ, which is purely governed by edge quantum numbers Nd and Nu. Our experimental setup is realized with a hexagonal boron nitride (hBN) encapsulated graphite gated single layer graphene device. For temperatures up to 35 mK, our measured GQ at ν = 2/3 and 3/5 (with CP modes) match the quantized values of non-equilibrated regime (Nd + Nu)κ0T, where κ0T is a quanta of GQ. With increasing temperature, GQ decreases and eventually takes the value of the equilibrated regime ∣Nd - Nu∣κ0T. By contrast, at ν = 1/3 and 2/5 (without CP modes), GQ remains robustly quantized at Ndκ0T independent of the temperature. Thus, measuring the quantized values of GQ in two regimes, we determine the edge quantum numbers, which opens a new route for finding the topological order of exotic non-Abelian FQH states.

9.
Nat Commun ; 13(1): 213, 2022 Jan 11.
Article in English | MEDLINE | ID: mdl-35017473

ABSTRACT

The presence of "upstream" modes, moving against the direction of charge current flow in the fractional quantum Hall (FQH) phases, is critical for the emergence of renormalized modes with exotic quantum statistics. Detection of excess noise at the edge is a smoking gun for the presence of upstream modes. Here, we report noise measurements at the edges of FQH states realized in dual graphite-gated bilayer graphene devices. A noiseless dc current is injected at one of the edge contacts, and the noise generated at contacts at length, L = 4 µm and 10 µm away along the upstream direction is studied. For integer and particle-like FQH states, no detectable noise is measured. By contrast, for "hole-conjugate" FQH states, we detect a strong noise proportional to the injected current, unambiguously proving the existence of upstream modes. The noise magnitude remains independent of length, which matches our theoretical analysis demonstrating the ballistic nature of upstream energy transport, quite distinct from the diffusive propagation reported earlier in GaAs-based systems.

10.
J Family Med Prim Care ; 11(10): 6197-6203, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36618193

ABSTRACT

Aim: To delineate and analyze the mortality from COVID -19 in our institute during the devastating second wave of pandemic. Settings and Design: A retrospective cohort analysis. Methods and Materials: A comprehensive mortality analysis of 142 laboratory-confirmed severe acute respiratory syndrome coronavirus 2-infected deceased patients from our hospital's medical records was done. These patients presented with severe disease at the time of admission and were managed in intensive care units. Statistical Analysis Used: Statistical Package for Social Sciences software, IBM manufacturer, Chicago, USA, version 21.0 was used. Results: The number of deceased males (82, 62.6%) was higher than females (53, 37.3%). Median age of deceased patient was 57 (44.25-69.75) years. Most frequent comorbidities were diabetes mellitus (42, 29.6%) and hypertension (41, 28.9%). Most common symptoms being shortness of breath (137, 96.5%), fever (94, 66.2%) and cough (73, 51.4%). Median peripheral capillary oxygen saturation (SpO2) at time of admission was 86% (77.25-90). Median time interval from symptom onset to admission in hospital was 3 (2.25-5) days. Neutrophil lymphocyte ratio was more than 5 in 117 (90.7%) patients. Complications seen were acute respiratory distress syndrome in 82.3%, acute liver injury in 58.4%, acute kidney injury in 26.7%, sepsis in 13.3% and acute cardiac injury in 12% patients. The median high-resolution computed tomography score was 20 (17-22). Conclusions: Male and elderly patients with underlying comorbidities had poorer outcome and involvement of multiple organ systems was common. A short time interval between symptom onset and admission/mortality, particularly encountered was worrisome.

11.
Phys Rev Lett ; 126(21): 216803, 2021 May 28.
Article in English | MEDLINE | ID: mdl-34114853

ABSTRACT

Transport through edge channels is responsible for conduction in quantum Hall (QH) phases. Robust quantized values of charge and thermal conductances dictated by bulk topology appear when equilibration processes become dominant. We report on measurements of electrical and thermal conductances of integer and fractional QH phases, realized in hexagonal boron nitride encapsulated graphite-gated bilayer graphene devices for both electron and hole doped sides with different valley and orbital symmetries. Remarkably, for complex edges at filling factors ν=5/3 and 8/3, closely related to the paradigmatic hole-conjugate ν=2/3 phase, we find quantized thermal conductance whose values (3κ_{0}T and 4κ_{0}T, respectively where κ_{0}T is the thermal conductance quantum) are markedly inconsistent with the values dictated by topology (1κ_{0}T and 2κ_{0}T, respectively). The measured thermal conductance values remain insensitive to different symmetries, suggesting its universal nature. Our findings are supported by a theoretical analysis, which indicates that, whereas electrical equilibration at the edge is established over a finite length scale, the thermal equilibration length diverges for strong electrostatic interaction. Our results elucidate the subtle nature of crossover from coherent, mesoscopic to topology-dominated transport.

12.
Phys Rev Lett ; 126(9): 096801, 2021 Mar 05.
Article in English | MEDLINE | ID: mdl-33750179

ABSTRACT

We report the discovery of electric-field-induced transition from a topologically trivial to a topologically nontrivial band structure in an atomically sharp heterostructure of bilayer graphene (BLG) and single-layer WSe_{2} per the theoretical predictions of Gmitra and Fabian [Phys. Rev. Lett. 119, 146401 (2017)PRLTAO0031-900710.1103/PhysRevLett.119.146401]. Through detailed studies of the quantum correction to the conductance in the BLG, we establish that the band-structure evolution arises from an interplay between proximity-induced strong spin-orbit interaction (SOI) and the layer polarizability in BLG. The low-energy carriers in the BLG experience an effective valley Zeeman SOI that is completely gate tunable to the extent that it can be switched on or off by applying a transverse displacement field or can be controllably transferred between the valence and the conduction band. We demonstrate that this results in the evolution from weak localization to weak antilocalization at a constant electronic density as the net displacement field is tuned from a positive to a negative value with a concomitant SOI-induced splitting of the low-energy bands of the BLG near the K(K^{'}) valley, which is a unique signature of the theoretically predicted spin-orbit valve effect. Our analysis shows that quantum correction to the Drude conductance in Dirac materials with strong induced SOI can only be explained satisfactorily by a theory that accounts for the SOI-induced spin splitting of the BLG low-energy bands. Our results demonstrate the potential for achieving highly tunable devices based on the valley Zeeman effect in dual-gated two-dimensional materials.

13.
ACS Nano ; 15(1): 916-922, 2021 Jan 26.
Article in English | MEDLINE | ID: mdl-33378173

ABSTRACT

Topological insulators, along with Chern insulators and quantum Hall insulator phases, are considered as paradigms for symmetry protected topological phases of matter. This article reports the experimental realization of the time-reversal invariant helical edge-modes in bilayer graphene/monolayer WSe2-based heterostructures-a phase generally considered as a precursor to the field of generic topological insulators. Our observation of this elusive phase depended crucially on our ability to create mesoscopic devices comprising both a moiré superlattice potential and strong spin-orbit coupling; this resulted in materials whose electronic band structure could be tuned from trivial to topological by an external displacement field. We find that the topological phase is characterized by a bulk bandgap and by helical edge-modes with electrical conductance quantized exactly to 2e2/h in zero external magnetic field. We put the helical edge-modes on firm ground through supporting experiments, including the verification of predictions of the Landauer-Büttiker model for quantum transport in multiterminal mesoscopic devices. Our nonlocal transport properties measurements show that the helical edge-modes are dissipationless and equilibrate at the contact probes. We achieved the tunability of the different topological phases with electric and magnetic fields, which allowed us to achieve topological phase transitions between trivial and multiple, distinct topological phases. We also present results of a theoretical study of a realistic model which, in addition to replicating our experimental results, explains the origin of the topological insulating bulk and helical edge-modes. Our experimental and theoretical results establish a viable route to realizing the time-reversal invariant Z2 topological phase of matter.

14.
ACS Chem Neurosci ; 11(22): 3772-3785, 2020 11 18.
Article in English | MEDLINE | ID: mdl-33125229

ABSTRACT

Parkinson's disease (PD) is the most common progressive neurodegenerative disease known to impart bradykinesia leading to diverse metabolic complications. Currently, scarcity of effective drug candidates against this long-term devastating disorder poses a big therapeutic challenge. Here, we have synthesized biocompatible, polycrystalline, and uniform piperine-coated gold nanoparticles (AuNPspiperine) to specifically target paraquat-induced metabolic complications both in Drosophila melanogaster and SH-SY5Y cells. Our experimental evidence clearly revealed that AuNPspiperine can effectively reverse paraquat-induced lethal effects in both in vitro and in vivo model systems of PD. AuNPspiperine were found to suppress oxidative stress and mitochondrial dysfunction, leading to inhibition of apoptotic cell death in paraquat-treated flies. AuNPspiperine were also found to protect SH-SY5Y cells against paraquat-induced toxicity at the cellular level preferably by maintaining mitochondrial membrane potential. Both experimental and computational data point to the possible influence of AuNPspiperine in regulating the homeostasis of parkin and p53 which may turn out to be the key factors in reducing PD symptoms. The findings of this work may facilitate the development of piperine-based nanoformulations against PD.


Subject(s)
Metal Nanoparticles , Neurodegenerative Diseases , Alkaloids , Animals , Benzodioxoles , Drosophila melanogaster , Gold , Metal Nanoparticles/toxicity , Oxidative Stress , Paraquat/toxicity , Piperidines , Polyunsaturated Alkamides
15.
Nanotechnology ; 31(41): 415101, 2020 Oct 09.
Article in English | MEDLINE | ID: mdl-32311687

ABSTRACT

The present article demonstrates the synthesis of the nanocomposite of reduced graphene oxide (rGO) with CdSe and CdSe/V2O5 core/shell quantum dots by a two-step facile synthesis approach and subsequently studies their relative biocompatibility in different cells. Various characterization techniques have been applied including transmission electron microscopy (TEM), an x-ray diffractometer (XRD) and Raman spectroscopy to confirm the successful formation of CdSe-rGO and CdSe/V2O5-rGO nanocomposites. The average sizes of CdSe and CdSe/V2O5 QDs have found to be ∼3 and 5.5 nm, respectively with a good dispersion over the surface of rGO nanosheets. A crystal phase change has occurred during the formation of the V2O5 shell over the surface of CdSe QDs and confirmed through XRD. Raman spectroscopy has shown some useful insight of the surface state of CdSe and consequent changes in the surface with V2O5 shell growth. Further, MTT and cell growth assays have been performed to analyze their biocompatibility in A549 and Hela cells with various concentrations of as-synthesized materials. Our results demonstrate the toxicity of CdSe-rGO nanocomposite to be substantially reduced by the growth of the V2O5 shell. The in vivo studies in Drosophila show a remarkable decrease in the reactive oxygen species (ROS) and apoptosis levels for a CdSe/V2O5-rGO composite as compared to a CdSe-rGO nanocomposite, which paves a promising pathway for the CdSe/V2O5-rGO nanocomposite to be used as an efficient biocompatible material.


Subject(s)
Biocompatible Materials/chemical synthesis , Cadmium Compounds/chemistry , Graphite/chemistry , Selenium Compounds/chemistry , Vanadium Compounds/chemistry , A549 Cells , Animals , Apoptosis/drug effects , Biocompatible Materials/chemistry , Biocompatible Materials/pharmacology , Cell Proliferation/drug effects , Drosophila , HeLa Cells , Humans , Nanocomposites/chemistry , Particle Size , Quantum Dots/chemistry , Reactive Oxygen Species/metabolism
16.
Neurochem Int ; 136: 104730, 2020 06.
Article in English | MEDLINE | ID: mdl-32201282

ABSTRACT

Prenatal stress (PNS) has its negative impact on both the infant hippocampal neurogenesis and pregnancy outcomes in the neonates that serves as a risk factor for postnatal depression in adult offsprings. Therefore, main objectives of the present study were to evaluate the effect of maternal chronic unpredictable mild stress (CUMS) on behavioural changes, levels of oxidative stress, changes in selective developmental signaling genes and neurogenesis in the adult brain of Wistar rats and its reversal through a selective non-ergoline D2 type dopamine receptor (D2R) agonist Ropinirole (ROPI). Effects of ROPI treatment on CUMS induced adult rats offspring were measured by assessment of behavioural tests (sucrose preference test and forced swim test), biomarkers of oxidative stress, protein expression of tyrosine hydroxylase (TH), mRNA expression of SHH, GSK-3ß, ß-catenin, Notch, brain-derived neurotrophic factor (BDNF), Dopamine receptor 2 (Drd2) and bromodeoxyuridine (BrdU) cell proliferation assay. The oxidative stress, protein and mRNA expression were determined in the hippocampus and prefrontal cortex while the BrdU cell proliferation was observed in the hippocampus of rat brain. PNS induced changes resulted in depression validated by the depression-like behaviours, increased oxidative stress, decreased TH expression, altered expression of selective developmental genes, along with the reduced hippocampal neurogenesis and BDNF expression in the brain of adult offsprings. Chronic ROPI treatment reversed those effects and was equally effective like Imipramine (IMI) treatment. So, the present study suggested that ROPI can be used as an antidepressant drug for the treatment of depressive disorders.


Subject(s)
Dopamine Agonists/pharmacology , Hippocampus/drug effects , Receptors, Dopamine D2/agonists , Stress, Psychological/chemically induced , Tyrosine 3-Monooxygenase/metabolism , Animals , Antidepressive Agents/pharmacology , Cell Proliferation/drug effects , Depression/drug therapy , Hippocampus/metabolism , Neurogenesis/drug effects , Neurogenesis/physiology , Oxidative Stress/drug effects , Rats, Wistar , Stress, Psychological/drug therapy , Stress, Psychological/metabolism
17.
Neurotherapeutics ; 16(3): 666-674, 2019 07.
Article in English | MEDLINE | ID: mdl-31376068

ABSTRACT

Alzheimer's disease (AD) is the most common progressive human neurodegenerative disorder affecting elderly population worldwide. Hence, prevention of AD has been a priority of AD research worldwide. Based on understanding of disease mechanism, different therapeutic strategies involving synthetic and herbal approaches are being used against AD. Among the herbal extract, Ginkgo biloba extract (GBE) is one of the most investigated herbal remedy for cognitive disorders and Alzheimer's disease (AD). Standardized extract of Ginkgo biloba is a popular dietary supplement taken by the elderly population to improve memory and age-related loss of cognitive function. Nevertheless, its efficacy in the prevention and treatment of dementia remains controversial. Specifically, the added effects of GBE in subjects already receiving "conventional" anti-dementia treatments have been to date very scarcely investigated. This review summarizes recent advancements in our understanding of the potential use of Ginkgo biloba extract in the prevention of AD including its antioxidant property. A better understanding of the mechanisms of action of GBE against AD will be important for designing therapeutic strategies, for basic understanding of the underlying neurodegenerative processes, and for a better understanding of the effectiveness and complexity of this herbal medicine.


Subject(s)
Alzheimer Disease/drug therapy , Antioxidants/therapeutic use , Nervous System Diseases/drug therapy , Neuroprotective Agents/therapeutic use , Plant Extracts/therapeutic use , Aged , Animals , Ginkgo biloba , Humans , Treatment Outcome
18.
Sci Adv ; 5(7): eaaw5798, 2019 Jul.
Article in English | MEDLINE | ID: mdl-31309156

ABSTRACT

The universal quantization of thermal conductance provides information on a state's topological order. Recent measurements revealed that the observed value of thermal conductance of the 5 2 state is inconsistent with either Pfaffian or anti-Pfaffian model, motivating several theoretical articles. Analysis has been made complicated by the presence of counter-propagating edge channels arising from edge reconstruction, an inevitable consequence of separating the dopant layer from the GaAs quantum well and the resulting soft confining potential. Here, we measured thermal conductance in graphene with atomically sharp confining potential by using sensitive noise thermometry on hexagonal boron-nitride encapsulated graphene devices, gated by either SiO2/Si or graphite back gate. We find the quantization of thermal conductance within 5% accuracy for ν = 1 ; 4 3 ; 2 and 6 plateaus, emphasizing the universality of flow of information. These graphene quantum Hall thermal transport measurements will allow new insight into exotic systems like even-denominator quantum Hall fractions in graphene.

19.
J Alzheimers Dis ; 69(2): 499-512, 2019.
Article in English | MEDLINE | ID: mdl-30958369

ABSTRACT

BACKGROUND: Alzheimer's disease (AD), the most prevalent neurodegenerative disorder, involves the formation of the extracellular amyloid-ß (Aß) plaques and intracellular neurofibrillary tangles. The current therapies against AD are symptomatic with limited benefits but associated with major side effects. Inhibition of self-aggregation of Aß peptides into higher order cross-ß structure is one of the potential therapeutic approach which may counter oligomerization of Aß peptide. OBJECTIVE: The present study aimed to evaluate the neuroprotective and anti-inflammatory potential of a synthetic Pro-Drug type peptide (PDp) against Aß-induced toxicity in rat model of AD. METHODS: Intra-hippocampal microinjection of toxic Aß40 (IHAß40) by stereotaxic surgery was performed in the male Sprague-Dawley rats to generate an Aß-induced AD model. Sub-chronic toxicity of synthetic PDp using hematological, biochemical, and histopathological parameters was investigated. Evaluation of PDp on Aß-induced neurodegeneration and neuroinflammation was performed. RESULTS: PDp inhibits plaque formation with increase in Nissl granule staining in the rat hippocampus. Aß-induced toxicity associated imbalance in reactive oxygen species and antioxidant enzymes activity such as superoxide dismutase and catalase in the rat brain was overcome by PDp treatment. Tau protein hyperphosphorylation was normalized with PDp treatment. Also, the neuroinflammatory response was suppressed with PDp treatment. CONCLUSION: The present study depicts the potential neuroprotective role of PDp against Aß-induced toxicity in rat. PDp inhibits plaque formation thereby normalizing oxidative stress, inhibiting tau protein hyperphosphorylation, and suppressing neuroinflammatory responses. Future studies done in this direction will pave way for new therapeutic strategies.


Subject(s)
Alzheimer Disease/chemically induced , Alzheimer Disease/drug therapy , Amyloid beta-Peptides/toxicity , Peptide Fragments/administration & dosage , Prodrugs/administration & dosage , Synthetic Drugs/administration & dosage , Alzheimer Disease/pathology , Animals , Avoidance Learning/drug effects , Avoidance Learning/physiology , Disease Models, Animal , Hippocampus/drug effects , Hippocampus/pathology , Male , Microinjections/methods , Peptide Fragments/toxicity , Random Allocation , Rats , Rats, Sprague-Dawley
20.
Sci Rep ; 9(1): 1305, 2019 02 04.
Article in English | MEDLINE | ID: mdl-30718708

ABSTRACT

Prenatal stress (PNS) has gained attention with regard to its impact on hippocampal neurogenesis in neonates which serves as a risk factor for postnatal neurodevelopmental deficits. Evidences from animal models have suggested that depression responsive hypothalamic-pituitary-adrenal (HPA) axis and its hormonal response via cortisol, is responsible for critical neurodevelopmental deficits in the offspring which is transduced due to gestational stress. But knowledge in the area of assessing the effects of maternal chronic unpredictable mild stress (CUMS) on neurogenesis and expression of some key signaling molecules in the offsprings are limited. We have used Wistar rats to induce PNS in offsprings by maternal CUMS during pregnancy. Prefrontal cortex (PFC) and hippocampus were assessed for biomarkers of oxidative stress, neurogenesis, neurodevelopmental signaling molecules and DNA damage in the male Wister offsprings. Our investigations resulted in sufficient evidences which prove how maternal psychological stress has widespread effect on the fetal outcomes via major physiological alteration in the antioxidant levels, neurogenesis, signaling molecules and DNA damage. PNS leads to the upregulation of GSK-3ß which in turn inhibited mRNA and protein expressions of sonic hedgehog (SHH), ß-catenin, Notch and brain derived neurotrophic factor (BDNF). The study explored multifaceted signaling molecules especially, GSK-3ß responsible for crosstalks between different neurodevelopmental molecules like SHH, Notch, BDNF and ß-catenin affecting neurodevelopment of the offsprings due to PNS.


Subject(s)
Glycogen Synthase Kinase 3 beta/metabolism , Neurogenesis , Stress, Physiological , Stress, Psychological , Animals , Animals, Newborn , Biomarkers , Cell Differentiation/genetics , Cell Proliferation/genetics , Corticosterone/metabolism , DNA Damage , Female , Hedgehog Proteins/metabolism , Hippocampus/metabolism , Male , Neurons/metabolism , Pregnancy , Rats , Single-Cell Analysis , Stress, Psychological/complications
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