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1.
Chem Rev ; 123(15): 9565-9652, 2023 Aug 09.
Artículo en Inglés | MEDLINE | ID: mdl-37428563

RESUMEN

Three-dimensional (3D) organic-inorganic lead halide perovskites have emerged in the past few years as a promising material for low-cost, high-efficiency optoelectronic devices. Spurred by this recent interest, several subclasses of halide perovskites such as two-dimensional (2D) halide perovskites have begun to play a significant role in advancing the fundamental understanding of the structural, chemical, and physical properties of halide perovskites, which are technologically relevant. While the chemistry of these 2D materials is similar to that of the 3D halide perovskites, their layered structure with a hybrid organic-inorganic interface induces new emergent properties that can significantly or sometimes subtly be important. Synergistic properties can be realized in systems that combine different materials exhibiting different dimensionalities by exploiting their intrinsic compatibility. In many cases, the weaknesses of each material can be alleviated in heteroarchitectures. For example, 3D-2D halide perovskites can demonstrate novel behavior that neither material would be capable of separately. This review describes how the structural differences between 3D halide perovskites and 2D halide perovskites give rise to their disparate materials properties, discusses strategies for realizing mixed-dimensional systems of various architectures through solution-processing techniques, and presents a comprehensive outlook for the use of 3D-2D systems in solar cells. Finally, we investigate applications of 3D-2D systems beyond photovoltaics and offer our perspective on mixed-dimensional perovskite systems as semiconductor materials with unrivaled tunability, efficiency, and technologically relevant durability.

2.
Soft Matter ; 2020 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-32975548

RESUMEN

We have observed fluid-fluid coexistence in 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) membrane containing 1-decanol, using different experimental techniques and membrane morphologies. This phase behavior is reversible and occurs over a temperature range just above the chain melting transition temperature of the membrane. Although earlier experimental studies and computer simulations have shown the ability of decanol to enhance lipid chain ordering, its potential to induce fluid-fluid coexistence in membranes has not been hitherto recognized. Being the only binary membrane system known so far to exhibit fluid-fluid coexistence, the present system can serve as a simple model to gain a better understanding of mechanisms that drive this unusual phase behavior, which is believed to play an important role in the functioning of cell membranes.

3.
South Med J ; 107(12): 774-9, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25502158

RESUMEN

OBJECTIVES: Diabetes mellitus is a significant risk factor for total cancer incidence and mortality. Metformin, a commonly used antidiabetic drug, has been shown to be protective against different types of cancers; however, its role in esophageal cancer is unknown. The goal of this study was to determine whether the use of metformin modifies the risk of development of esophageal adenocarcinoma in patients with Barrett esophagus. METHODS: Patients with diagnoses of Barrett esophagus and esophageal cancer were identified during a 20-year period. Demographic and clinical data were collected. The outcome variable was esophageal adenocarcinoma. Univariate analysis was performed using two-sample t tests for continuous variables or the Fisher exact test for categorical variables. Multiple logistic regression analysis was then performed using the significant variables. RESULTS: A total of 583 patients were identified with the diagnosis of Barrett esophagus or esophageal adenocarcinoma from 1992 to 2012. Of these, 115 had esophageal adenocarcinoma and 468 had Barrett esophagus. Age, smoking, and diabetes mellitus were found to be significant risk factors for the development of esophageal cancer with the following results: age (P < 0.001), smoking (P = 0.003), diabetes mellitus (P = 0.007). Statin use was protective against the development of cancer with P = 0.001. Metformin use was neither associated with an increased nor a decreased risk of esophageal cancer. CONCLUSIONS: The three independent variables that predicted progression of Barrett esophagus to esophageal adenocarcinoma in our study were older age, smoking, and diabetes mellitus. Statin use showed protective effect against development of esophageal adenocarcinoma. Metformin use did not demonstrate any statistically significant protective effect.


Asunto(s)
Adenocarcinoma/prevención & control , Esófago de Barrett/patología , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Neoplasias Esofágicas/prevención & control , Hipoglucemiantes/uso terapéutico , Metformina/uso terapéutico , Lesiones Precancerosas/patología , Adenocarcinoma/etiología , Adenocarcinoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Esófago de Barrett/complicaciones , Estudios de Casos y Controles , Diabetes Mellitus Tipo 2/complicaciones , Neoplasias Esofágicas/etiología , Neoplasias Esofágicas/patología , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Lesiones Precancerosas/complicaciones , Estudios Retrospectivos , Factores de Riesgo
4.
Cureus ; 15(1): e33907, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36819397

RESUMEN

The genu valgum is one of the anomalies of the lower extremities in the coronal plane (knocked knees). Children might be vulnerable to it as well. It may also be hereditary, with females being more likely to develop it. A 14-year-old female patient had severe genu valgum anomalies of the bilateral lower extremities. The patient is in pain, unable to stand, and sit on the ground. On the numerical pain rating scale (NPRS), the level of pain was rated as 8/10 while activity and 5/10 during rest. The patient received physiotherapy treatment for a total of six weeks, which included exercises, electrotherapy, and gait training. As a result, the patient experienced a reduction in pain, which was rated 2/10 while activity and 1/10 during rest, and an improvement in range of motion, and functional activities. Correcting the gait, enhancing the quality of life, and restoring functional ability are all significantly impacted by physiotherapy. Based on the current case study, conventional physical therapy improved functional goals gradually and significantly, which in turn potentially aided in a successful recovery.

5.
Indian J Otolaryngol Head Neck Surg ; 75(3): 2168-2171, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37636743

RESUMEN

BACKGROUND: Allergic rhinitis (AR) is a symptomatic condition of the nose, caused by an IgE-mediated inflammation of the nasal membranes. Allergic rhinitis is further split into two categories, based on the duration of symptoms: intermittent (IAR) or persistent (PER) disease. Oral or topical antihistamines and topical nasal steroids are the most popular and efficient treatments for allergic rhinitis. METHODS: The present prospective comparative study was done between December 2021 to November 2022, with 64 subjects of PER divided into groups A and B. Group A patients received Fluticasone propionate (50 mcg) combined with Azelastine (140 mcg) nasal spray, whereas Group B patients received standalone Fluticasone propionate (50 mcg) nasal spray. RESULTS: In both groups, the difference in mean TSS between the beginning and end of the 4-week study period was statistically significant (p for both < 0.05). After 4 weeks of treatment, Group A had a TSS of 2.02 ± 0.83 and Group B was at 3.80 ± 1.49; the difference between them was statistically significant (p < 0.05). CONCLUSIONS: According to results obtained from the current study, while both fluticasone propionate with azelastine nasal spray and standalone fluticasone propionate nasal spray are widely used for control of symptoms in PER, the former offers better results with significant reduction of symptoms when compared to the latter.

6.
Cureus ; 15(9): e46094, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37900478

RESUMEN

BACKGROUND: Surgical site infections (SSIs) are an opposing result of surgery and account for the majority of healthcare-related infections worldwide. It is one of the most common complications associated with open-spine surgery and is associated with high rates of mortality and high demand for healthcare resources. Surgical site infections are the result of a variety of reasons, which is why a range of prevention strategies have been proposed. Intraoperative wound irrigation (IOWI) is a simple procedure that involves moving a solution through an open wound to help hydrate the tissue. It is a type of prophylactic wound irrigation. It removes and dilutes bodily fluids, bacteria, and cellular debris. It may also act as a bactericidal agent when used with antibiotics and antiseptics. AIMS AND OBJECTIVES: To evaluate the incidence of SSI in lumbar spine surgeries by comparing IOWI with normal saline containing gentamicin (NS-G) and normal saline (NS) alone. MATERIALS AND METHOD: A hospital-based retrospective study was conducted among 40 patients who underwent elective lumbar spine surgery at the Department of Orthopaedics, RL Jalappa Hospital Centre, Kolar, Karnataka, India. RESULT: Out of the total participants enrolled, 60% were males and 40% were females. There was no statistically significant difference found between mean age, mean BMI, mean hemoglobin level, mean WBC counts, and mean fasting blood sugar (FBS) levels among both groups. The overall prevalence of SSI among patients was 25%. In Group A (NS-G), the prevalence of SSI was 15%, and in Group B (NS), it was 35%. In total, 17.5% of study participants had superficial SSI, while 7.5% had deep SSI. CONCLUSION: Gentamicin, an aminoglycoside antibiotic, is bactericidal and efficient against gram-positive organisms like Staphylococcus, the most frequent pathogen causing SSI in spine surgery. During lumbar spine surgery, IOWI with saline and gentamicin before closure is more effective in preventing SSI than simple saline irrigation.

7.
Nat Commun ; 14(1): 3797, 2023 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-37365175

RESUMEN

Achieving high solar-to-hydrogen (STH) efficiency concomitant with long-term durability using low-cost, scalable photo-absorbers is a long-standing challenge. Here we report the design and fabrication of a conductive adhesive-barrier (CAB) that translates >99% of photoelectric power to chemical reactions. The CAB enables halide perovskite-based photoelectrochemical cells with two different architectures that exhibit record STH efficiencies. The first, a co-planar photocathode-photoanode architecture, achieved an STH efficiency of 13.4% and 16.3 h to t60, solely limited by the hygroscopic hole transport layer in the n-i-p device. The second was formed using a monolithic stacked silicon-perovskite tandem, with a peak STH efficiency of 20.8% and 102 h of continuous operation before t60 under AM 1.5G illumination. These advances will lead to efficient, durable, and low-cost solar-driven water-splitting technology with multifunctional barriers.

8.
Science ; 377(6613): 1425-1430, 2022 09 23.
Artículo en Inglés | MEDLINE | ID: mdl-36137050

RESUMEN

Realizing solution-processed heterostructures is a long-enduring challenge in halide perovskites because of solvent incompatibilities that disrupt the underlying layer. By leveraging the solvent dielectric constant and Gutmann donor number, we could grow phase-pure two-dimensional (2D) halide perovskite stacks of the desired composition, thickness, and bandgap onto 3D perovskites without dissolving the underlying substrate. Characterization reveals a 3D-2D transition region of 20 nanometers mainly determined by the roughness of the bottom 3D layer. Thickness dependence of the 2D perovskite layer reveals the anticipated trends for n-i-p and p-i-n architectures, which is consistent with band alignment and carrier transport limits for 2D perovskites. We measured a photovoltaic efficiency of 24.5%, with exceptional stability of T99 (time required to preserve 99% of initial photovoltaic efficiency) of >2000 hours, implying that the 3D/2D bilayer inherits the intrinsic durability of 2D perovskite without compromising efficiency.

9.
Toxics ; 9(12)2021 Dec 03.
Artículo en Inglés | MEDLINE | ID: mdl-34941767

RESUMEN

Arsenic, a potent carcinogen and neurotoxin, affects over 200 million people globally. Current detection methods are laborious, expensive, and unscalable, being difficult to implement in developing regions and during crises such as COVID-19. This study attempts to determine if a relationship exists between soil's hyperspectral data and arsenic concentration using NASA's Hyperion satellite. It is the first arsenic study to use satellite-based hyperspectral data and apply a classification approach. Four regression machine learning models are tested to determine this correlation in soil with bare land cover. Raw data are converted to reflectance, problematic atmospheric influences are removed, characteristic wavelengths are selected, and four noise reduction algorithms are tested. The combination of data augmentation, Genetic Algorithm, Second Derivative Transformation, and Random Forest regression (R2=0.840 and normalized root mean squared error (re-scaled to [0,1]) = 0.122) shows strong correlation, performing better than past models despite using noisier satellite data (versus lab-processed samples). Three binary classification machine learning models are then applied to identify high-risk shrub-covered regions in ten U.S. states, achieving strong accuracy (=0.693) and F1-score (=0.728). Overall, these results suggest that such a methodology is practical and can provide a sustainable alternative to arsenic contamination detection.

10.
Mater Today Proc ; 47: 3716-3719, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33614415

RESUMEN

The COVID-19 coronavirus pandemic is an unparalleled threat intoday's quickly developing climate, and we face it as a global community. Like climate change, it is challenging our resilience from environmental health, social security, and government, to knowledge exchange and economic policy in all sectors of the economy and all fields of growth. So much as climate change, everybody's coming together would require the initiative. Throughout Europe and America, several organizations have mobilized to ensure that the neediest are not left behind, encouraging emergencies and disruptions avoidance and preparedness. The coronavirus outbreak has highlighted the growing community's strengths and vulnerabilities that it has influenced, and has provided us with the ability to benefit from each other's accomplishments and shortcomings. The comparison graph has also been shown in this paper displaying European and American scenarios. The globe might feel smaller amid disaster states and global travel bans, but it is a period when teamwork and looking outward were never more relevant.

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