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1.
Curr Diabetes Rev ; 2022 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-35538797

RESUMO

BACKGROUND: The division of care responsibilities between parents and children with type 1 diabetes, and an optimal transfer of responsibilities from parent to child over time are assumed to be key for optimal diabetes outcomes during childhood and adolescence. However, an overview of instruments assessing this division as well as their psychometric qualities is currently lacking. OBJECTIVE: To 1) identify all existing instruments, 2) evaluate their psychometric properties, and 3) provide an overview of scoring methods. METHODS: Pubmed and PsycINFO were searched using an a priori defined search string. Peer-reviewed studies in English using an instrument assessing the division of diabetes care responsibilities between children (6-18 years) and parents were included. In total, 84 of 725 articles qualified, covering 62 unique samples. RESULTS: Thirteen questionnaires were identified. The Diabetes Family Responsibility Questionnaire (DFRQ) was most frequently used across studies. Instructions, content and number of tasks, response options, and scoring methods varied across questionnaires. Recent studies often adapted questionnaires, contributing to the heterogeneity across measures. Overall, reporting and quality of psychometric properties was suboptimal. CONCLUSION: The division of diabetes care responsibilities can be operationalized with various instruments, each having its strengths and weaknesses but all with limited psychometric support. To measure the division of diabetes care responsibilities more adequately, an updated version of the popular DFRQ or a new scale needs to be developed and evaluated.

2.
J Palliat Care ; : 8258597221095986, 2022 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-35469500

RESUMO

BACKGROUND: Palliative care aims to improve or maintain quality of life for patients with life-limiting or life-threatening diseases. Limited research shows that palliative care is associated with reduced intensive care unit length of stay and use of high-cost resources. METHODS: This was an observational, non-experimental comparison group study on all patients 18 years or older admitted to any intensive care unit (ICU) at Memorial Hermann - Texas Medical Center for 7 to 30 days from August 2013 to December 2015. Length of stay (LOS) and hospital costs were compared between the treatment group of patients with palliative care in the ICU and the control group of patients with usual care in the ICU. To adjust for confounding of the palliative care consultation on LOS and hospital cost, an inverse probability of treatment weighted method was conducted. Generalized linear models using gamma distribution and log link were estimated. All costs were converted to 2015 US dollars. RESULTS: Mean LOS was 13 days and mean total hospital costs were USD 58,378. In adjusted and weighted analysis, LOS for the treatment group was 8% longer compared to the control group. The mean total hospital cost was estimated to decrease by 21% for the treatment group versus the control group. We found a reduction of USD 33,783 in hospital costs per patient who died in the hospital and reduction of USD 9113 per patient discharged alive. CONCLUSION: Palliative care consultation was associated with a reduction in the total cost of hospital care for patients with life-limiting or life-threatening diseases.

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 275: 121117, 2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-35364411

RESUMO

Potato is one of the most important food crops worldwide in terms of human consumption. However, potato farmers employ a variety of pesticides to protect crops from harmful insects and illnesses, and difenoconazole is a commonly used one that has severe effects on human health and the environment. Therefore, detecting difenoconazole quickly and correctly is critical. In this work, we fabricated AgNPs/cicada wing substrates using natural cicada segments, decorated with silver nanoparticles for surface-enhanced Raman scattering (SERS) measurements to detect trace amounts of difenoconazole in potatoes. Results indicated that a linear relationship with the coefficient of detection (R2) of 0.987 and the detection limit (LOD) of 0.016 ppm was observed by targeting a distinctive peak at 808 cm-1 and logarithmic difenoconazole concentrations of 0.1 to 100 ppm. In addition, difenoconazole LODs in potatoes were 63 µg/kg, lower than those specified by the EU (0.1 mg/kg) and Vietnam (4 mg/kg) utilizing this new technique. Therefore, this proposed SERS method could be used to detect difenoconazole in potatoes at trace levels.


Assuntos
Hemípteros , Nanopartículas Metálicas , Solanum tuberosum , Animais , Dioxolanos , Humanos , Prata , Análise Espectral Raman/métodos , Triazóis
5.
Molecules ; 27(7)2022 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-35408437

RESUMO

Libraries of microorganisms have served as a cornerstone of therapeutic drug discovery, though the continued re-isolation of known natural product chemical entities has remained a significant obstacle to discovery efforts. A major contributing factor to this redundancy is the duplication of bacterial taxa in a library, which can be mitigated through the use of a variety of DNA sequencing strategies and/or mass spectrometry-informed bioinformatics platforms so that the library is created with minimal phylogenetic, and thus minimal natural product overlap. IDBac is a MALDI-TOF mass spectrometry-based bioinformatics platform used to assess overlap within collections of environmental bacterial isolates. It allows environmental isolate redundancy to be reduced while considering both phylogeny and natural product production. However, manually selecting isolates for addition to a library during this process was time intensive and left to the researcher's discretion. Here, we developed an algorithm that automates the prioritization of hundreds to thousands of environmental microorganisms in IDBac. The algorithm performs iterative reduction of natural product mass feature overlap within groups of isolates that share high homology of protein mass features. Employing this automation serves to minimize human bias and greatly increase efficiency in the microbial strain prioritization process.


Assuntos
Produtos Biológicos , Biologia Computacional , Bactérias/genética , Produtos Biológicos/química , Biblioteca Gênica , Humanos , Filogenia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
6.
Opt Express ; 30(7): 10443-10455, 2022 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-35473011

RESUMO

Fiber specklegram sensors (FSSs) traditionally use statistical methods to analyze specklegrams obtained from fibers for sensing purposes, but can suffer from limitations such as vulnerability to noise and lack of dynamic range. In this paper we demonstrate that deep learning improves the analysis of specklegrams for sensing, which we show here for both air temperature and water immersion length measurements. Two deep neural networks (DNNs); a convolutional neural network and a multi-layer perceptron network, are used and compared to a traditional correlation technique on data obtained from a multimode fiber exposed-core fiber. The ability for the DNNs to be trained against a random noise source such as specklegram translations is also demonstrated.

7.
Pharmaceutics ; 14(4)2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35456588

RESUMO

As a widely distributed parasitic nematode of ruminants, Haemonchus contortus has become resistant to most anthelmintic classes, there has been a major demand for new compounds against H. contortus and related nematodes. Recent phenotypic screening has revealed two compounds, designated as BLK127 and HBK4, that are active against H. contortus larvae. The present study was designed to assess the activity of these compounds against H. contortus eggs and adults, hepatotoxicity in rats and sheep, as well as biotransformation in H. contortus adults and the ovine liver. Both compounds exhibited no inhibitory effect on the hatching of eggs. The benzyloxy amide BLK127 significantly decreased the viability of adults in sensitive and resistant strains of H. contortus and showed no hepatotoxic effect, even at the highest concentration tested (100 µM). In contrast, HBK4 had no impact on the viability of H. contortus adults and exhibited significant hepatotoxicity. Based on these findings, HBK4 was excluded from further studies, while BLK127 seems to be a potential candidate for a new anthelmintic. Consequently, biotransformation of BLK127 was tested in H. contortus adults and the ovine liver. In H. contortus, several metabolites formed via hydroxylation, hydrolysis and glycosidation were identified, but the extent of biotransformation was low, and the total quantity of the metabolites formed did not differ significantly between the sensitive and resistant strains. In contrast, ovine liver cells metabolized BLK127 more extensively with a glycine conjugate of 4-(pentyloxy)benzoic acid as the main BLK127 metabolite.

8.
J Affect Disord ; 307: 171-177, 2022 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-35331824

RESUMO

BACKGROUND: Though the association between anxiety disorders and suicidal behavior is well-described, the impact of anxiety symptoms on suicidal thoughts and behaviors (STB) across different mood disorders is still unclear. METHODS: We performed a registry-based retrospective study utilizing outcome measure data collected by the National Network of Depression Centers (NNDC), a nationwide nonprofit consortium of 26 leading clinical and academic member centers in the United States. The sample consisted of 2607 outpatients with mood disorders (major depressive disorder or bipolar disorders). Demographic and clinical variables were compared based on the presence or absence of STB and severity of anxiety symptoms (minimal, mild, moderate, and severe). Univariate and multivariable logistic regressions were conducted to examine the correlations of STB, considering multicollinearity. RESULTS: Patients with mild, moderate, and severe anxiety symptoms had higher odds of STB than those with minimal symptoms. Gender, marital status, age, and depressive symptoms were other strong predictors of STB. There was no difference in the odds of STB between patients with major depressive disorder (MDD) and those with bipolar disorders (BD). However, the odds of suicidal ideation were slightly lower among patients with BD than those with MDD. LIMITATIONS: Our sample was comprised only of outpatients, limiting the generalization of our findings. Other limitations include the lack of structured interviews for diagnostic characterization of the patients and the utilization of data on anxiety and mood obtained solely through self-report scales. CONCLUSIONS: We found a cross-sectional association between the severity of anxiety symptoms and STB among patients with mood disorders. This study demonstrates the need for a suicide risk assessment in patients with mood disorders reporting anxiety symptoms.


Assuntos
Transtorno Depressivo Maior , Ideação Suicida , Ansiedade , Estudos Transversais , Transtorno Depressivo Maior/epidemiologia , Humanos , Transtornos do Humor/epidemiologia , Estudos Retrospectivos , Fatores de Risco
9.
J Wildl Dis ; 58(2): 341-347, 2022 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-35255143

RESUMO

The secondary metabolite emodin, produced by the widely distributed invasive shrub known as the common buckthorn (Rhamnus cathartica), has been shown to produce deformities and mortality in invertebrates, fish, and amphibian larvae. Here, we describe the effects on the liver of green frog (Lithobates clamitans) tadpoles after 21 d of exposure to high concentrations of emodin in a controlled environment. Histopathologic analysis showed fibrosis, bile duct proliferation, hepatocellular swelling, and accumulations of flocculent material consistent with emodin within the gall bladder and bile ducts of exposed individuals. The extensive fibrosis produced probably impeded the blood flow within the portal triads, limiting the detoxification function of the liver and resulting in hepatocellular necrosis and premature death for the individuals exposed. Exposure to emodin in the environment could represent a significant threat to developing amphibian larvae and contribute to local declines of populations.


Assuntos
Carcinoma Hepatocelular , Emodina , Neoplasias Hepáticas , Rana clamitans , Rhamnus , Animais , Carcinoma Hepatocelular/veterinária , Emodina/metabolismo , Fibrose , Larva , Neoplasias Hepáticas/veterinária
10.
Med Image Anal ; 78: 102422, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35339951

RESUMO

Multiphase CT scanning of the liver is performed for several clinical applications; however, radiation exposure from CT scanning poses a nontrivial cancer risk to the patients. The radiation dose may be reduced by determining the scan range of the subsequent scans by the location of the target of interest in the first scan phase. The purpose of this study is to present and assess an automatic method for determining the scan range for multiphase CT scans. Our strategy is to first apply a CNN-based method for detecting the liver in 2D slices, and to use a liver range search algorithm for detecting the liver range in the scout volume. The target liver scan range for subsequent scans can be obtained by adding safety margins achieved from Gaussian liver motion models to the scan range determined from the scout. Experiments were performed on 657 multiphase CT volumes obtained from multiple hospitals. The experiment shows that the proposed liver detection method can detect the liver in 223 out of a total of 224 3D volumes on average within one second, with mean intersection of union, wall distance and centroid distance of 85.5%, 5.7 mm and 9.7 mm, respectively. In addition, the performance of the proposed liver detection method is comparable to the best of the state-of-the-art 3D liver detectors in the liver detection accuracy while it requires less processing time. Furthermore, we apply the liver scan range generation method on the liver CT images acquired from radiofrequency ablation and Y-90 transarterial radioembolization (selective internal radiation therapy) interventions of 46 patients from two hospitals. The result shows that the automatic scan range generation can significantly reduce the effective radiation dose by an average of 14.5% (2.56 mSv) compared to manual performance by the radiographer from Y-90 transarterial radioembolization, while no statistically significant difference in performance was found with the CT images from intra RFA intervention (p = 0.81). Finally, three radiologists assess both the original and the range-reduced images for evaluating the effect of the range reduction method on their clinical decisions. We conclude that the automatic liver scan range generation method is able to reduce excess radiation compared to the manual performance with a high accuracy and without penalizing the clinical decision.


Assuntos
Processamento de Imagem Assistida por Computador , Radioisótopos de Ítrio , Humanos , Processamento de Imagem Assistida por Computador/métodos , Fígado/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos
11.
Front Oral Health ; 3: 817249, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35330821

RESUMO

The epithelial barrier at mucosal sites comprises an important mechanical protective feature of innate immunity, and is intimately involved in communicating signals of infection/tissue damage to inflammatory and immune cells in these local environments. A wide array of antimicrobial factors (AMF) exist at mucosal sites and in secretions that contribute to this innate immunity. A non-human primate model of ligature-induced periodontitis was used to explore characteristics of the antimicrobial factor transcriptome (n = 114 genes) of gingival biopsies in health, initiation and progression of periodontal lesions, and in samples with clinical resolution. Age effects and relationship of AMF to the dominant members of the oral microbiome were also evaluated. AMF could be stratified into 4 groups with high (n = 22), intermediate (n = 29), low (n = 18) and very low (n = 45) expression in healthy adult tissues. A subset of AMF were altered in healthy young, adolescent and aged samples compared with adults (e.g., APP, CCL28, DEFB113, DEFB126, FLG2, PRH1) and were affected across multiple age groups. With disease, a greater number of the AMF genes were affected in the adult and aged samples with skewing toward decreased expression, for example WDC12, PGLYRP3, FLG2, DEFB128, and DEF4A/B, with multiple age groups. Few of the AMF genes showed a >2-fold increase with disease in any age group. Selected AMF exhibited significant positive correlations across the array of AMF that varied in health and disease. In contrast, a rather limited number of the AMF significantly correlated with members of the microbiome; most prominent in healthy samples. These correlated microbes were different in younger and older samples and differed in health, disease and resolution samples. The findings supported effects of age on the expression of AMF genes in healthy gingival tissues showing a relationship to members of the oral microbiome. Furthermore, a dynamic expression of AMF genes was related to the disease process and showed similarities across the age groups, except for low/very low expressed genes that were unaffected in young samples. Targeted assessment of AMF members from this large array may provide insight into differences in disease risk and biomolecules that provide some discernment of early transition to disease.

12.
Nat Prod Res ; : 1-9, 2022 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-35337228

RESUMO

Sixteen sesquiterpenoids including two new ones, homalolides A - B (1‒2), were firstly isolated from the methanolic extract of the rhizomes of Homalomena pendula collected in Vietnam. The structures and relative stereochemistry of new compounds were elucidated by 1D-/2D-NMR, IR, UV and HRESIMS analyses. The GCMS experiment demonstrated that homalolide A (1) is an artifact due to the methylation during methanolic extraction process. All isolates (1‒16) were tested for their inhibitory activities against lipopolysaccharide-induced nitric oxide production in the RAW 264.7 macrophage cell line. Compounds 1, 3, 6‒8, 10‒12 displayed moderate inhibitory effect on NO production with IC50 values ranging from 35.41 to 64.06 µM.

13.
J Parkinsons Dis ; 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35253778

RESUMO

BACKGROUND: Mutations in PTEN-induced putative kinase 1 (PINK1) cause autosomal recessive Parkinson's disease (PD) and contribute to the risk of sporadic PD. However, the relationship between PD-related PINK1 mutations and alpha-synuclein (α-syn) aggregation-a main pathological component of PD-remains unexplored. OBJECTIVE: To investigate whether α-syn pathology is exacerbated in the absence of PINK1 after α-syn preformed fibril (PFF) injection in a PD mouse model and its effects on neurodegeneration. METHODS: In this study, 10-week-old Pink1 knockout (KO) and wildtype (WT) mice received stereotaxic unilateral striatal injection of recombinant mouse α-syn PFF. Then, α-syn pathology progression, inflammatory responses, and neurodegeneration were analyzed via immunohistochemistry, western blot analysis, and behavioral testing. RESULTS: After PFF injection, the total α-syn levels significantly increased, and pathological α-syn was markedly aggregated in Pink1 KO mice compared with Pink1 WT mice. Then, earlier and more severe neuronal loss and motor deficits occurred. Moreover, compared with WT mice, Pink1 KO mice had evident microglial/astrocytic immunoreactivity and prolonged astrocytic activation, and a higher rate of protein phosphatase 2A phosphorylation, which might explain the greater α-syn aggravation and neuronal death. CONCLUSION: The loss of Pink1 function accelerated α-syn aggregation, accumulation and glial activation, thereby leading to early and significant neurodegeneration and behavioral impairment in the PD mouse model. Therefore, our findings support the notion that PINK1 dysfunction increases the risk of synucleinopathy.

14.
J Clin Oncol ; : JCO2102108, 2022 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-35263119

RESUMO

PURPOSE: Tubo-ovarian cancer (TOC) is a sentinel cancer for BRCA1 and BRCA2 pathogenic variants (PVs). Identification of a PV in the first member of a family at increased genetic risk (the proband) provides opportunities for cancer prevention in other at-risk family members. Although Australian testing rates are now high, PVs in patients with TOC whose diagnosis predated revised testing guidelines might have been missed. We assessed the feasibility of detecting PVs in this population to enable genetic risk reduction in relatives. PATIENTS AND METHODS: In this pilot study, deceased probands were ascertained from research cohort studies, identification by a relative, and gynecologic oncology clinics. DNA was extracted from archival tissue or stored blood for panel sequencing of 10 risk-associated genes. Testing of deceased probands ascertained through clinic records was performed with a consent waiver. RESULTS: We identified 85 PVs in 84 of 787 (11%) probands. Familial contacts of 39 of 60 (65%) deceased probands with an identified recipient (60 of 84; 71%) have received a written notification of results, with follow-up verbal contact made in 85% (33 of 39). A minority of families (n = 4) were already aware of the PV. For many (29 of 33; 88%), the genetic result provided new information and referral to a genetic service was accepted in most cases (66%; 19 of 29). Those who declined referral (4 of 29) were all male next of kin whose family member had died more than 10 years before. CONCLUSION: We overcame ethical and logistic challenges to demonstrate that retrospective genetic testing to identify PVs in previously untested deceased probands with TOC is feasible. Understanding reasons for a family member's decision to accept or decline a referral will be important for guiding future TRACEBACK projects.

15.
J Nutr Sci Vitaminol (Tokyo) ; 68(1): 32-38, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35228493

RESUMO

Type 2 diabetes mellitus (T2DM) has been increasing rapidly in Vietnam as well as world-wide. One of the major causes of the condition is low fiber intake. It is difficult to eat large amounts of vegetables every day to reach a sufficient amount of fiber but Textured Soybean Protein is rich in fiber. The study aimed to examine the effectiveness of Textured Soybean Protein consumption on T2DM patients. In this randomized controlled trial, 47 T2DM patients were divided into an intervention group (n=24) and a control group (n=23). The intervention group were asked to consume 40 g Textured Soybean Protein in 2 dishes for 4 wk. The control group continued their usual diet. Fasting blood samples were drawn before and after intervention to measure fasting plasma glucose (FPG), fructosamine, low density lipoprotein-cholesterol (LDL-C), high density lipoprotein-cholesterol (HDL-C), total cholesterol (T-C), and triglycerides (TG). A 3-day food record was conducted at 1 wk before (baseline) and at the last week (final) of the intervention period. In the Textured Soybean Protein consumption group, there was a significant decrease in fructosamine (363±86 µmol/L to 347±82 µmol/L, p=0.03), T-C (5.2±0.9 mmol/L to 4.8±0.8 mmol/L, p=0.02) and TG (3.5±2.2 mmol/L to 2.8±2.0 mmol/L, p=0.02). Total energy intake in the two groups did not change significantly. There was a shift in the dietary pattern of the Textured Soybean Protein consumption group; lipid intake showed a significant decrease (p=0.001) and fiber intake increased by 6 g (p<0.001). The consumption of Textured Soybean Protein in the diet could have favorable effects in improving glycemic and lipid concentrations in T2DM patients.


Assuntos
Diabetes Mellitus Tipo 2 , Proteínas de Soja , Glicemia/metabolismo , HDL-Colesterol , Humanos , Soja , Triglicerídeos
16.
Int J Mol Sci ; 23(6)2022 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-35328541

RESUMO

Excess amounts of redox stress and failure to regulate homeostatic levels of reactive species are associated with several skin pathophysiologic conditions. Nonmalignant cells are assumed to cope better with higher reactive oxygen and nitrogen species (RONS) levels. However, the effect of periodic stress on this balance has not been investigated in fibroblasts in the field of plasma medicine. In this study, we aimed to investigate intrinsic changes with respect to cellular proliferation, cell cycle, and ability to neutralize the redox stress inside fibroblast cells following periodic redox stress in vitro. Soft jet plasma with air as feeding gas was used to generate plasma-activated medium (PAM) for inducing redox stress conditions. We assessed cellular viability, energetics, and cell cycle machinery under oxidative stress conditions at weeks 3, 6, 9, and 12. Fibroblasts retained their usual physiological properties until 6 weeks. Fibroblasts failed to overcome the redox stress induced by periodic PAM exposure after 6 weeks, indicating its threshold potential. Periodic stress above the threshold level led to alterations in fibroblast cellular processes. These include consistent increases in apoptosis, while RONS accumulation and cell cycle arrest were observed at the final stages. Currently, the use of NTP in clinical settings is limited due to a lack of knowledge about fibroblasts' behavior in wound healing, scar formation, and other fibrotic disorders. Understanding fibroblasts' physiology could help to utilize nonthermal plasma in redox-related skin diseases. Furthermore, these results provide new information about the threshold capacity of fibroblasts and an insight into the adaptation mechanism against periodic oxidative stress conditions in fibroblasts.


Assuntos
Fibroblastos , Dermatopatias , Proliferação de Células , Meios de Cultura/farmacologia , Fibroblastos/metabolismo , Homeostase , Humanos , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Dermatopatias/metabolismo
17.
J Clin Lab Anal ; : e24355, 2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35312118

RESUMO

BACKGROUND: The COVID-19 pandemic caused by SARS-CoV-2 remains public health burdens and many unresolved issues worldwide. Molecular assays based on real-time RT-PCR are critical for the detection of SARS-CoV-2 in clinical specimens from patients suspected of COVID-19. OBJECTIVE: We aimed to establish and validate an in-house real-time RT-PCR for the detection of SARS-CoV-2. METHODOLOGY: Primers and probes sets in our in-house real-time RT-PCR assay were designed in conserved regions of the N and E target genes. Optimized multiplex real-time RT-PCR assay was validated using the first WHO International Standard (NIBSC code: 20/146) and evaluated clinical performance. RESULTS: The limit of detection validated using the first WHO International Standard was 159 IU/ml for both E and N target genes. The evaluation of clinical performance on 170 clinical samples showed a positive percent agreement of 100% and the negative percent agreement of 99.08% for both target genes. The Kappa value of 0.99 was an excellent agreement, the strong correlation of Ct values observed between two tests with r2  = 0.84 for the E gene and 0.87 for the N gene. Notably, we assessed on 60 paired saliva and nasopharyngeal samples. The overall agreement was 91.66%, and Kappa value of 0.74 showed a high agreement between two types of samples. When using nasopharyngeal swabs as the reference standard, positive percent agreement, and negative percent agreement were 91.83% and 90.90%, respectively. CONCLUSION: In the present study, we established and validated an in-house real-time RT-PCR for molecular detection of SARS-CoV-2 in a resource-limited country.

18.
Med Phys ; 49(4): 2212-2219, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35195908

RESUMO

BACKGROUND: While microbubble contrast agents (MCAs) are commonly used in ultrasound (US), they are inherently limited to vascular targets due to their size. Alternatively, phase-changing nanodroplet contrast agents (PNCAs) can be delivered as nanoscale agents (i.e., small enough to extravasate), but when exposed to a US field of sufficient mechanical index (MI), they convert to MCAs, which can be visualized with high contrast using nonlinear US. PURPOSE: To investigate the effect of perfluorocarbon (PFC) core composition and presence of cholesterol in particle coatings on stability and image contrast generated from acoustic activation of PNCAs using high-frequency US suitable for clinical imaging. METHODS: PNCAs with varied core compositions (i.e., mixtures of perfluoropentane [C5] and/or perfluorohexane [C6]) and two coating formulations (i.e., with and without cholesterol) were characterized and investigated for thermal/temporal stability and postactivation, nonlinear US contrast in phantom and in vivo environments. Through hydrophone measurements and nonlinear numerical modeling, MI was estimated for pulse sequences used for PNCA activation. RESULTS: All PNCA compositions were characterized to have similar diameters (249-267 nm) and polydispersity (0.151-0.185) following fabrication. While PNCAs with majority C5 core composition showed higher levels of spontaneous signal (i.e., not due to US activation) in phantoms than C6-majority PNCAs, all compositions were stable during imaging experiments. When activating PNCAs with a 12.3-MHz US pulse (MI = 1.1), C6-core particles with cholesterol-free coatings (i.e., CF-C6-100 particles) generated a median contrast of 3.1, which was significantly higher (p < 0.001) than other formulations. Further, CF-C6-100 particles were activated in a murine model, generating US contrast ≥ $ \ge $ 3.4. CONCLUSION: C6-core PNCAs can provide high-contrast US imaging with minimal nonspecific activation in phantom and in vivo environments.


Assuntos
Meios de Contraste , Fluorcarbonetos , Acústica , Animais , Camundongos , Microbolhas , Ultrassonografia/métodos
19.
Biomacromolecules ; 23(3): 1423-1432, 2022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35188757

RESUMO

Highly stretchable electrically conductive hydrogels have been extensively researched in recent years, especially for applications in strain and pressure sensing, electronic skin, and implantable bioelectronic devices. Herein, we present a new cross-linked complex coacervate approach to prepare conductive hydrogels that are both highly stretchable and compressive. The gels involve a complex coacervate between carboxylated nanogels and branched poly(ethylene imine), whereby the latter is covalently cross-linked by poly(ethylene glycol) diglycidyl ether (PEGDGE). Inclusion of graphene nanoplatelets (Gnp) provides electrical conductivity as well as tensile and compressive strain-sensing capability to the hydrogels. We demonstrate that judicious selection of the molecular weight of the PEGDGE cross-linker enables the mechanical properties of these hydrogels to be tuned. Indeed, the gels prepared with a PEGDGE molecular weight of 6000 g/mol defy the general rule that toughness decreases as strength increases. The conductive hydrogels achieve a compressive strength of 25 MPa and a stretchability of up to 1500%. These new gels are both adhesive and conformal. They provide a self-healable electronic circuit, respond rapidly to human motion, and can act as strain-dependent sensors while exhibiting low cytotoxicity. Our new approach to conductive gel preparation is efficient, involves only preformed components, and is scalable.


Assuntos
Grafite , Dispositivos Eletrônicos Vestíveis , Adesivos , Condutividade Elétrica , Humanos , Hidrogéis
20.
Bioresour Technol ; 350: 126899, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35217159

RESUMO

Fatty acid ethyl esters (FAEEs) have gained increasing attention as a replacement for traditional fossil fuels in the recent years. Here, we report the efficient upgrading of ethanol to FAEEs from Pseudomonas putida KT2440, using ethanol as the sole carbon source. First, the wax synthase (WS) encoded by the atfA gene from Acinetobacter baylyi ADP1 was expressed in P. putida KT2440. Second, the flux from ethanol towards acetyl-CoA was increased by expression of the acetaldehyde dehydrogenase (ada) from Dickeya zeae. By using dodecane overlay to capture FAEEs, 1.2 g/L of FAEEs with a yield of 152.09 mg FAEEs/g ethanol were produced. Culture optimization enhanced the FAEEs contents up to 1.6 g/L in shake flask and 4.3 g/L in a fed-batch fermenter. In summary, our study provides a basis for combining the bioethanol production process with the efficient upgrading of ethanol to biodiesel.


Assuntos
Engenharia Metabólica , Pseudomonas putida , Ésteres/metabolismo , Etanol/metabolismo , Ácidos Graxos/metabolismo , Pseudomonas putida/genética , Pseudomonas putida/metabolismo
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