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1.
Chemosphere ; 288(Pt 2): 132528, 2021 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-34637864

RESUMO

Global warming issues, rapid fossil fuel diminution, and increasing worldwide energy demands have diverted accelerated attention in finding alternate sources of biofuels and energy to combat the energy crisis. Bioconversion of lignocellulosic biomass has emerged as a prodigious way to produce various renewable biofuels such as biodiesel, bioethanol, biogas, and biohydrogen. Ideal microbial hosts for biofuel synthesis should be capable of using high substrate quantity, tolerance to inhibiting substances and end-products, fast sugar transportation, and amplified metabolic fluxes to yielding enhanced fermentative bioproduct. Genetic manipulation and microbes' metabolic engineering are fascinating strategies for the economical production of next-generation biofuel from lignocellulosic feedstocks. Metabolic engineering is a rapidly developing approach to construct robust biofuel-producing microbial hosts and an important component for future bioeconomy. This approach has been widely adopted in the last decade for redirecting and revamping the biosynthetic pathways to obtain a high titer of target products. Biotechnologists and metabolic scientists have produced a wide variety of new products with industrial relevance through metabolic pathway engineering or optimizing native metabolic pathways. This review focuses on exploiting metabolically engineered microbes as promising cell factories for the enhanced production of advanced biofuels.

2.
Gene ; 805: 145910, 2021 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-34419567

RESUMO

Ethylene is an important regulatory phytohormone for sex differentiation and flower development. As the rate-limiting enzyme encoding genes in ethylene biosynthesis, ACS gene family has been well studied in cucumber; however, little is known in other cucurbit crops, such as melon and watermelon, which show diverse sex types in the field. Here, we identified and characterized eight ACS genes each in the genomes of melon and watermelon. According to the conserved serine residues at C-terminal, all the ACS genes could be characterized into three groups, which were supported by the exon-intron organizations and conserved motif distributions. ACS genes displayed diverse tissue-specific expression patterns among four melon and three watermelon sex types. Furthermore, a comparative expression analysis in the shoot apex identified orthologous pairs with potential functions in sex determination, e.g., ACS1s and ACS6s. All ACS orthologs in melon and watermelon exhibited similar expression patterns in monoecious and gynoecious genotypes, except for ACS11s and ACS12s. As expected, the majority of ACS genes were responsive to exogenous ethephon; however, some orthologs exhibited opposite expression patterns, such as ACS1s, ACS9s, and ACS10s. Collectively, our findings provide valuable ACS candidates related to flower development in various sex types of melon and watermelon.


Assuntos
Cucurbitaceae/genética , Etilenos/metabolismo , Liases/metabolismo , Diferenciação Sexual/genética , Citrullus/genética , Citrullus/metabolismo , Cucumis sativus/genética , Cucumis sativus/metabolismo , Cucurbitaceae/metabolismo , Expressão Gênica/genética , Perfilação da Expressão Gênica/métodos , Regulação da Expressão Gênica de Plantas/genética , Genes de Plantas/genética , Genótipo , Liases/genética , Filogenia , Proteínas de Plantas/genética , Diferenciação Sexual/fisiologia
3.
Int J Mol Sci ; 22(16)2021 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-34445115

RESUMO

The SWEET (Sugars Will Eventually be Exported Transporter) proteins are a novel family of sugar transporters that play key roles in sugar efflux, signal transduction, plant growth and development, plant-pathogen interactions, and stress tolerance. In this study, 22 ClaSWEET genes were identified in Citrullus lanatus (Thunb.) through homology searches and classified into four groups by phylogenetic analysis. The genes with similar structures, conserved domains, and motifs were clustered into the same groups. Further analysis of the gene promoter regions uncovered various growth, development, and biotic and abiotic stress responsive cis-regulatory elements. Tissue-specific analysis showed most of the genes were highly expressed in male flowers and the roots of cultivated varieties and wild cultivars. In addition, qRT-PCR results further imply that ClaSWEET proteins might be involved in resistance to Fusarium oxysporum infection. Moreover, a significantly higher expression level of these genes under various abiotic stresses suggests its multifaceted role in mediating plant responses to drought, salt, and low-temperature stress. The genome-wide characterization and phylogenetic analysis of ClaSWEET genes, together with the expression patterns in different tissues and stimuli, lays a solid foundation for future research into their molecular function in watermelon developmental processes and responses to biotic and abiotic stresses.


Assuntos
Transporte Biológico/genética , Citrullus/genética , Genoma de Planta/genética , Família Multigênica/genética , Proteínas de Plantas/genética , Estresse Fisiológico/genética , Açúcares/metabolismo , Fusarium/genética , Regulação da Expressão Gênica de Plantas/genética , Estudo de Associação Genômica Ampla/métodos , Filogenia , Raízes de Plantas/genética , Regiões Promotoras Genéticas/genética
4.
Int J Pharm ; 605: 120815, 2021 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-34153441

RESUMO

A 3D printed assembly of hollow microneedles (HMNs) array, conjoined with a reservoir void, was designed and additively manufactured using stereolithography (SLA) technology utilizing a proprietary class-I resin. The HMNs array was utilized for transdermal delivery of high molecular weight antibiotics, i.e., rifampicin (Mw 822.94 g/mol), which suffers from gastric chemical instability, low bioavailability, and severe hepatotoxicity. HMNs morphology was designed with sub-apical holes present in a quarter of the needle tip to improve its mechanical strength and integrity of the HMNs array. The HMNs array was characterized by optical microscopy and electron microscopy to ascertain the print quality and uniformity across the array. The system was also subjected to mechanical characterization for failure and penetration analyses. The ex vivo permeation and consequent transport of rifampicin across porcine skin were systematically evaluated. Finally, in vivo examinations of rifampicin administration through the microneedle reservoir system in SD rats revealed efficient penetration and desired bioavailability.


Assuntos
Rifampina , Estereolitografia , Administração Cutânea , Animais , Sistemas de Liberação de Medicamentos , Microinjeções , Agulhas , Ratos , Ratos Sprague-Dawley , Pele , Suínos
5.
Artigo em Inglês | MEDLINE | ID: mdl-34148675

RESUMO

PURPOSE: Shigella is the second leading cause of diarrhoeal mortality especially in children <5 years of age in African and Asian countries. Rapid changes are occurring in the epidemiology of shigellosis and Shigella are increasingly becoming highly drug resistant. To determine the serogroup distribution and antimicrobial resistance of Shigella isolated at our tertiary care centre in North India. METHODS: A retrospective study was conducted where demographic details along with antimicrobial susceptibility data of Shigella isolated from stool specimens from 1st January 2015 till 31st December 2019 were retrieved from records and analyzed by WHONET 2019 software. RESULTS: Shigella species was isolated in 1.31% (n = 137) of a total of 10,456 stool samples. Males predominated (n = 82; 59.8%) and majority of cases were admitted (n = 94; 68.6%). Children ≤5 years of age (n = 47; 34.3%) were the most commonly affected. Adults in the 21-40 age group contributed 27% of cases (n = 37). Overall, Shigella flexneri (n = 87; 63.5%) was the most common serogroup followed by non-agglutinable Shigella (n = 28; 20.4%) while Shigella sonnei (n = 12, 8.8%) and Shigella boydii (n = 9, 6.6%) fluctuated over the years. Shigella dysenteriae reappeared in 2019 after a hiatus of ten years. Overall, 45.3% (n = 62) of isolates were multidrug resistant to CLSI recommended drugs and high resistance was noted for ampicillin/amoxicillin (68.1%), cotrimoxazole (75.8%) ciprofloxacin (61.5%) and ceftriaxone/cefotaxime (45.2%). CONCLUSIONS: Shigella have become highly drug resistant to fluoroquinolones and cephalosporins. Community based studies are required to truly assess the burden of AMR in India.

6.
Biomater Sci ; 9(9): 3284-3292, 2021 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33949367

RESUMO

Encapsulation of single cells in a thin hydrogel provides a more precise control of stem cell niches and better molecular transport. Despite the recent advances in microfluidic technologies to allow encapsulation of single cells, existing methods rely on special crosslinking agents that are pre-coated on the cell surface and subject to the variation of the cell membrane, which limits their widespread adoption. This work reports a high-throughput single-cell encapsulation method based on the "tip streaming" mode of alternating current (AC) electrospray, with encapsulation efficiencies over 80% after tuned centrifugation. Dripping with multiple cells is curtailed due to gating by the sharp conic meniscus of the tip streaming mode that only allows one cell to be ejected at a time. Moreover, the method can be universally applied to both natural and synthetic hydrogels, as well as various cell types, including human multipotent mesenchymal stromal cells (hMSCs). Encapsulated hMSCs maintain good cell viability over an extended culture period and exhibit robust differentiation potential into osteoblasts and adipocytes. Collectively, electrically induced tip streaming enables high-throughput encapsulation of single cells with high efficiency and universality, which is applicable for various applications in cell therapy, pharmacokinetic studies, and regenerative medicine.


Assuntos
Hidrogéis , Células-Tronco Mesenquimais , Diferenciação Celular , Sobrevivência Celular , Humanos , Microfluídica
7.
Anal Chem ; 93(16): 6456-6462, 2021 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-33861566

RESUMO

Rapid point-of-care (POC) quantification of low virus RNA load would significantly reduce the turn-around time for the PCR test and help contain a fast-spreading epidemic. Herein, we report a droplet digital PCR (ddPCR) platform that can achieve this sensitivity and rapidity without bulky lab-bound equipment. The key technology is a flattened pipette tip with an elliptical cross-section, which extends a high aspect-ratio microfluidic chip design to pipette scale, for rapid (<5 min) generation of several thousand monodispersed droplets ∼150 to 350 µm in size with a CV of ∼2.3%. A block copolymer surfactant (polyoxyalkylene F127) is used to stabilize these large droplets in oil during thermal cycling. At this droplet size and number, positive droplets can be counted by eye or imaged by a smartphone with appropriate illumination/filtering to accurately quantify up to 100 target copies. We demonstrate with 2019 nCoV-PCR assay LODs of 3.8 copies per 20 µL of sample and a dynamic range of 4-100 copies. The ddPCR platform is shown to be inhibitor resistant with spiked saliva samples, suggesting RNA extraction may not be necessary. It represents a rapid 1.5-h POC quantitative PCR test that requires just a pipette equipped with elliptical pipette tip, a commercial portable thermal cycler, a smartphone, and a portable trans-illuminator, without bulky and expensive micropumps and optical detectors that prevent POC application.


Assuntos
COVID-19 , Sistemas Automatizados de Assistência Junto ao Leito , Humanos , Reação em Cadeia da Polimerase em Tempo Real , SARS-CoV-2 , Carga Viral
8.
Genes (Basel) ; 12(3)2021 02 24.
Artigo em Inglês | MEDLINE | ID: mdl-33668231

RESUMO

Dirigent (DIR) proteins are induced under various stress conditions and involved in sterio- and regio-selective coupling of monolignol. A striking lack of information about dirigent genes in cucurbitaceae plants underscores the importance of functional characterization. In this study, 112 DIR genes were identified in six species, and 61 genes from major cultivated species were analyzed. DIRs were analyzed using various bioinformatics tools and complemented by expression profiling. Phylogenetic analysis segregated the putative DIRs into six distinctively known subgroups. Chromosomal mapping revealed uneven distribution of genes, whereas synteny analysis exhibited that duplication events occurred during gene evolution. Gene structure analysis suggested the gain of introns during gene diversification. Gene ontology (GO) enrichment analysis indicates the participation of proteins in lignification and pathogen resistance activities. We also determined their organ-specific expression levels in three species revealing preferential expression in root and leaves. Furthermore, the number of CmDIR (CmDIR1, 6, 7 and 12) and ClDIR (ClDIR2, 5, 8, 9 and 17) genes exhibited higher expression in resistant cultivars after powdery mildew (PM) inoculation. In summary, based on the expression and in-silico analysis, we propose a role of DIRs in disease resistance mechanisms.


Assuntos
Cucurbitaceae , Resistência à Doença , Filogenia , Doenças das Plantas , Folhas de Planta , Proteínas de Plantas , Raízes de Plantas , Cucurbitaceae/genética , Cucurbitaceae/metabolismo , Cucurbitaceae/microbiologia , Doenças das Plantas/genética , Doenças das Plantas/microbiologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia
9.
Clin Transplant ; 35(5): e14271, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33638186

RESUMO

BACKGROUND: Continuous Renal Replacement Therapy (CRRT) is often used to support the intraoperative course during liver transplantation (LT) for patients with HRS. However, the use of intraoperative CRRT (IOCRRT) is not without its problems. Living donor liver transplantation (LDLT) is a planned operation and is possible without IOCRRT as the recipient can be optimized. AIM: To study the peritransplant outcomes of patients with CLD and HRS undergoing LT without IOCRRT. METHODS: Analysis of LT program database for perioperative outcomes in patients with HRS from Feb 2017 to Dec 2018. RESULTS: 87/363 (23.9%) adult LDLT patients had HRS, of whom 31 (35.6%) did not respond (NR) to standard medical therapy (SMT) prior to LT. Modified perioperative protocol enabled the NR patients (who were sicker and in persistent renal failure) to undergo LT without IOCRRT. Postoperative renal dysfunction was similar (2 in NR and 2 in R) at 1 year. Post-LT survival was also not different at one month (83.87% in NR and 87.5% in R [p = .640]) and at 1 year (77% in NR vs 80.4% in non-responders [p = .709]). CONCLUSION: IOCRRT can be avoided in HRS patients undergoing LDLT without compromising their outcomes (post-LT survival and RD), even in patients who have not responded to SMT, preoperatively.


Assuntos
Síndrome Hepatorrenal , Transplante de Fígado , Transplantes , Adulto , Humanos , Doadores Vivos , Terapia de Substituição Renal , Resultado do Tratamento
10.
Microb Pathog ; 154: 104792, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33636321

RESUMO

Acylated homoserine lactones (AHL) such as N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12 HSL) and N-butyryl-l-homoserine lactone (C4 HSL) are the most common autoinducer molecules in Pseudomonas aeruginosa. These AHL molecules not only regulate the expression of virulence factors but also have been shown to interfere with the host cell and modulate its functions. Recently, we reported that 3-oxo-C12 HSL but not C4 HSL causes cytosolic Ca2+ rise and ROS production in platelets. In this study, we examined the potential of AHLs to induce apoptosis in the human blood platelet. Our result showed that 3-oxo-C12 HSL but not C4 HSL causes phosphatidylserine (PS) exposure, mitochondrial dysfunction (mitochondrial transmembrane potential loss, and mitochondrial permeability transition pore (mPTP) formation). Besides, 3-oxo-C12 HSL also inhibited thrombin-induced platelet aggregation and clot retraction. The pretreatment of an intracellular calcium chelator BAPTA-AM or ROS inhibitor (DPI) significantly attenuated the 3-oxo-C12 HSL induced apoptotic characters such as PS exposure and mitochondrial dysfunctions. These data, including our previous findings, confirmed that 3-oxo-C12 HSL induced intracellular Ca2+ mediated ROS production results in the activation and subsequent induction of apoptotic features in platelets. Our results demonstrated that the 3-oxo-C12 HSL modulates the functions of platelets that may cause severe thrombotic complications in P. aeruginosa infected individuals.


Assuntos
Plaquetas , Cálcio , 4-Butirolactona/análogos & derivados , Apoptose , Homosserina/análogos & derivados , Humanos , Lactonas , Pseudomonas aeruginosa , Espécies Reativas de Oxigênio
11.
Chem Biol Drug Des ; 97(2): 325-340, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32909340

RESUMO

Spiropyrans have been extensively investigated because of their thermo- and photochromic characteristics, but their biotherapeutic properties have not been explored much. We report anti-proliferative properties of a novel 3,3'-azadimethylene dinaphthospiropyran 11. Dibenzospiropyrans and dinaphthospiropyrans were synthesized by a simple and expedient method using acid-catalyzed aldol condensation of salicylaldehyde and 2-hydroxy-1-naphthaldehyde, respectively, with cyclic ketones. Together with structural elucidation by 2D NMR and X-ray crystallography studies, we provide a putative mechanism for their formation. Compound 11 showed solvatochromism and exhibited altered spectral characteristics depending on the pH. In acidic conditions, 11 remains in open form, whereas upon alkalinization it reverts back to closed form. Based on the in vitro anti-proliferative activity in H441, HCT-116, MiaPaCa-2, and Panc-1 cancer cell lines, 11 was submitted to further investigation. It reduced HCT116 colonosphere formation and demonstrated induction of caspase cascade, suggesting apoptosis. In vitro proliferation assays also suggested that HCl and trifluoroacetate salts of 11 are more effective. Treatment of mice carrying HCT-116 xenografts with 11 (5 µg/day, intraperitoneal for 3 weeks) suppressed tumor growth by 62%. Overall, the results reveal a new series of structurally complex, but relatively easy to synthesize molecules of which compound 11 represents a lead for anticancer development.

12.
PLoS One ; 15(12): e0244088, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33362284

RESUMO

BACKGROUND: In response to longstanding concerns around the quality of female sterilization services provided at public health facilities in India, the Government of India issued standards and quality assurance guidelines for female sterilization services in 2014. However, implementation remains a challenge. The Maternal and Child Survival Program rolled out a package of competency-based trainings, periodic mentoring, and easy-to-use job aids in parts of five states to increase service providers' adherence to key practices identified in the guidelines. METHODS: The study employed a before-and-after quasi-experimental design with a matched comparison arm to examine the effect of the intervention on provider practices in two states: Odisha and Chhattisgarh. Direct observations of female sterilization services were conducted in selected public health facilities, using a checklist of 30 key practices, at two points in time. Changes in adherence to key practices from baseline to endline were compared at 12 intervention and 12 comparison facilities using a difference in difference analysis. RESULTS: Several key practices were well-established prior to the intervention, with adherence levels over 90% at baseline, including hemoglobin and urine testing, use of sterile surgical gloves and instruments, and recommended surgical technique. However, adherence to many other practices was extremely low at baseline. The program significantly increased adherence to nine practices, including those related to ascertaining client's medical eligibility, client-provider interaction, the consent process, and post-operative care. The greatest improvement was observed in the provision of written instructions for clients prior to discharge. At endline, however, adherence remained below 50% for 14 practices. CONCLUSION: Low adherence to key practices at baseline confirmed the need for quality improvement interventions in female sterilization services. While the intervention improved adherence to certain practices around admission and post-operative care, inadequate human resources and infrastructure, among other factors, may have blunted the impact of the intervention.


Assuntos
Atenção à Saúde , Fidelidade a Diretrizes , Melhoria de Qualidade , Qualidade da Assistência à Saúde , Esterilização Reprodutiva , Adulto , Feminino , Humanos , Índia
13.
Lab Chip ; 20(22): 4273-4284, 2020 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-33090162

RESUMO

In this study, an ion depleted zone created by an ion-selective membrane was used to impose a high and uniform constant extracellular potential over an entire ∼1000 cell rat cardiomyocyte (rCM) colony on-a-chip to trigger synchronized voltage-gated ion channel activities while preserving cell viability, thus extending single-cell voltage-clamp ion channel studies to an entire normalized colony. Image analysis indicated that rCM beating was strengthened and accelerated (by a factor of ∼2) within minutes of ion depletion and the duration of contraction and relaxation phases was significantly reduced. After the initial synchronization, the entire colony responds collectively to external potential changes such that beating over the entire colony can be activated or deactivated within 0.1 s. These newly observed collective dynamic responses, due to simultaneous ion channel activation/deactivation by a uniform constant-potential extracellular environment, suggest that perm-selective membrane modules on cell culture chips can facilitate studies of extracellular cardiac cell electrical communication and how ion-channel related pathologies affect cardiac cell synchronization. The future applications of this new technology can lead to better drug screening platforms for cardiotoxicity as well as platforms that can facilitate synchronized maturation of pluripotent stem cells into colonies with high electrical connectivity.


Assuntos
Canais Iônicos , Miócitos Cardíacos , Animais , Avaliação Pré-Clínica de Medicamentos , Ratos
14.
Phys Chem Chem Phys ; 22(37): 21360-21368, 2020 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-32940303

RESUMO

Two-dimensional covalent organic frameworks (2D-COFs) belong to a new class of molecular materials that have attracted huge attention in recent years due to their analogous nature to graphene. In this work, we present a systematic study of the electronic structure, carrier mobility and work function of imine based 2D-COFs. We identify these 2D-COFs as a new class of semiconducting materials with tunable electronic/optoelectronic properties and significant mobility. The results show that by rationally doping 2D-COFs at the molecular level, it is possible to control their structural and optoelectronic responses. Cohesive energy calculations revealed that all the studied 2D-COFs are thermodynamically stable. Also, the calculated binding energy of 2D-COFs on HOPG was found to be less than 1 eV, which indicates that the COFs do not interact strongly with HOPG, and it will not affect their electronic properties. Additionally, we have synthesized a 2,4,6-pyrimidinetriamine based 2D-COF and experimentally measured its band gap using scanning tunnelling spectroscopy. The experimentally measured band gap is found to be in good agreement with theoretical results.

15.
J Clin Imaging Sci ; 10: 45, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32874750

RESUMO

Objectives: Peripheral arterial disease (PAD) leads to narrowing and hardening of arteries which leads to increased risk of lower extremity amputation. Hence, the accuracy of non-invasive diagnostic methods such as calcium scoring and color Doppler needs to be assessed in comparison to the gold standard dual-energy computed tomography (DECT) angiography. This study aims to evaluate the accuracy of color Doppler and calcium scoring when compared to DECT angiography in the assessment of PAD of the lower limb. It is a cross- sectional retrospective study. Material and Methods: The study included 55 patients aged between 40 and 70 years. All the patients with symptoms suggestive of PAD underwent color Doppler study of lower limb arterial system. Afterward, the patient underwent CT angiography. The first plain images were taken for calcium scoring following which contrast was given and further images were taken. Results: As compared to CT angiography assessment, Doppler assessment was 88.1% sensitive but only 69.2% specific with diagnostic accuracy of 83.6%. For angiographically detected atheromatous changes, color Doppler had sensitivity and specificity of 86.2% and 76.9%. The derived cutoff value >149.1 of calcium score in lower limb arteries was in 100% agreement with CT angiography detected PAD, whereas, for atheromatous changes, total calcium score at a cutoff value of >842.2 had sensitivity and specificity of 75.9% and 80.8%. Conclusion: Calcium scoring as compared to color Doppler has a higher diagnostic efficacy for the detection of DECT angiography confirmed PAD, whereas calcium score lacks adequate sensitivity at projected cutoff in the evaluation of atheromatous changes.

16.
Am J Med Case Rep ; 8(10): 337-340, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32851129

RESUMO

Coronavirus Disease-2019 (COVID-19) is currently a public health emergency and has been listed by the World Health Organization (WHO) as a pandemic. It has commonly been associated with pulmonary manifestations and there is a growing body of evidence of multisystem involvement of the virus. As evidenced by various case reports and cohort studies, COVID-19-associated coagulopathy has been a common manifestation amongst the critically ill and has been associated with increased mortality. The presence of venous thromboembolic events in patients who are critically ill due to COVID-19 has prompted the adoption of anticoagulation regimens aimed at preventing thromboembolic phenomena. Coagulation abnormalities have also been implicated in the progression and the severity of COVID-19 related acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC). There is strong evidence that D-dimer levels help predict which patients are at risk of thromboembolic events, progression to ARDS, DIC, immune dysregulation and mortality. We will review the utility of D-dimer as screening tool and in the risk stratification of COVID-19 patients prone to developing thromboembolic events, DIC, immune dysregulation and death. To date, the studies that have been published show the presence of elevated D-dimer levels in both the adult and pediatric populations and the measured level correlates with disease severity. Studies have also shown the relative increase of D-dimer levels in non-survivors compared to survivors. The elevation of D-dimer levels has shown to guide clinical decision making, namely the initiation of therapeutic anticoagulation and mortality benefit in patients with severe COVID-19 pneumonia compared to severe non COVID-19 pneumonia. Although the current body of literature suggested the use of D-dimer as a risk stratification tool and as a test to augment clinical judgement regarding the initiation of anticoagulation, randomized control trials are needed to fully understand the relationship between COVID-19 infection and the efficacy of D-dimer assays in clinical decision making.

17.
Am J Med Case Rep ; 8(10): 341-347, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32851130

RESUMO

The understanding of neural regulation of the cardiovascular function and the implications of a "Heart-Brain Axis "has been a topic of interest for clinicians for many years. Electrocardiographic (ECG) and structural cardiac changes, ranging from mild, asymptomatic, transient alteration in cardiovascular function to severe, irreversible, and potentially life-threatening injury, can actually be a manifestation of several neurological disorders. When managing cardiac disorders, a high index of clinical suspicion, detailed history-taking and physical examination skills, and an extensive workup that covers both cardiac and non-cardiac causes should be utilized. It is important to consider that cardiovascular dysfunction of an underlying neurological etiology may lead to difficulty in diagnosing and optimizing treatment of the latter. We report the case of a middle-aged female with the chief complaint of syncope preceded by a headache with no focal neurological deficits, originally diagnosed with- and whose syncope was attributed to sinus bradycardia and type I sinoatrial (SA) exit block on ECG. Subsequently, when the patient became altered, however, computer tomography (CT) angiography revealed subarachnoid hemorrhage (SAH) with middle cerebral artery aneurysm. This presentation emphasizes the importance of tabulating neurological injury as one of the differential diagnoses while managing ECG changes in cardiovascular disease (CVD), as missing and delaying the former can result in disastrous consequences.

18.
Am J Med Case Rep ; 8(9): 315-320, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32671194

RESUMO

Infective endocarditis (IE) is a serious medical condition with a high morbidity and mortality rate. Staphylococcus aureus is the most common etiologic organism in IE. While echocardiography plays an important role in diagnosis and management of IE, the electrocardiogram (ECG) is helpful in determination of disease progression as well as in prognostication. We present a case of a 72-year-old man who was diagnosed with IE following methicillin resistant Staphylococcus aureus (MRSA) bacteremia. The course of hospitalization was complicated with multiple septic-embolic strokes and aortic root abscess. Serial ECG revealed PR prolongation and new onset left bundle branch block (LBBB) before the patient became terminal. Our case highlights the utility of serial ECGs monitoring in the patients with IE that may reveal subtle ECG findings, such as PR prolongation and LBBB. These findings which might serve as a clue of the presence of peri-annular extension of IE, help in prognostication and aid in the therapeutic decision-making such as early surgical intervention in these high-risk patients with poor prognosis. In this report, we also present the pathophysiologic mechanisms underlining the ECG changes in patients with aortic valve endocarditis.

19.
ACS Omega ; 5(24): 14203-14211, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32596556

RESUMO

Since the breakthrough of graphene, 2D materials have engrossed tremendous research attention due to their extraordinary properties and potential applications in electronic and optoelectronic devices. The high carrier mobility in the semiconducting material is critical to guarantee a high switching speed and low power dissipation in the corresponding device. Here, we review significant recent advances and important new developments in the carrier mobility of 2D materials based on theoretical investigations. We focus on some of the most widely studied 2D materials, their development, and future applications. Based on the current progress in this field, we conclude the review by providing challenges and an outlook in this field.

20.
Indian J Radiol Imaging ; 30(1): 59-63, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32476751

RESUMO

Background: Bone marrow edema is assumed to be caused as a result of trabecular microfractures that are detected by MRI. As MRI is not widely available in countries like India, this study aims to encourage the use of DECT in detection of bone edema as evidence with comparable efficiency to MRI. Aim: To assess the diagnostic accuracy of dual-energy CT in detecting bone marrow edema in patients of trauma of lower limb and correlate it with MRI. Setting and Design: It is a cross-sectional study. Materials and Methods: The study included 40 patients of age 15-70 years irrespective of sex. All the patients of lower extremity trauma underwent DECT and MRI evaluation after clinical evaluation. All the images were postprocessed on a work station and were further evaluated by a radiologist. Results: Mean attenuation at fractured site observed by Dual energy CT was found to be significantly higher as compared to that at adjacent site (170.75 ± 33.99 vs. 19.73 ± 22.50 HU). The sensitivity and specificity of dual energy CT as compared to MRI in detecting bone marrow edema were 94.1% and 91.3%, respectively. Of the 40 cases enrolled in the study, agreement of MRI and Dual energy CT was observed in 37 (92.5%). Conclusion: Dual energy CT can be an effective alternative to MRI in the detection of bone marrow edema in patients of lower limb trauma. Dual energy CT can also be used in patients in whom MRI is contraindicated.

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