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1.
J Am Chem Soc ; 146(10): 6706-6720, 2024 Mar 13.
Artículo en Inglés | MEDLINE | ID: mdl-38421812

RESUMEN

Two-dimensional (2D) halide perovskites are exquisite semiconductors with great structural tunability. They can incorporate a rich variety of organic species that not only template their layered structures but also add new functionalities to their optoelectronic characteristics. Here, we present a series of new methylammonium (CH3NH3+ or MA)-based 2D Ruddlesden-Popper perovskites templated by dimethyl carbonate (CH3OCOOCH3 or DMC) solvent molecules. We report the synthesis, detailed structural analysis, and characterization of four new compounds: MA2(DMC)PbI4 (n = 1), MA3(DMC)Pb2I7 (n = 2), MA4(DMC)Pb3I10 (n = 3), and MA3(DMC)Pb2Br7 (n = 2). Notably, these compounds represent unique structures with MA as the sole organic cation both within and between the perovskite sheets, while DMC molecules occupy a tight space between the MA cations in the interlayer. They form hydrogen-bonded [MA···DMC···MA]2+ complexes that act as spacers, preventing the perovskite sheets from condensing into each other. We report one of the shortest interlayer distances (∼5.7-5.9 Å) in solvent-incorporated 2D halide perovskites. Furthermore, the synthesized crystals exhibit similar optical characteristics to other 2D perovskite systems, including narrow photoluminescence (PL) signals. The density functional theory (DFT) calculations confirm their direct-band-gap nature. Meanwhile, the phase stability of these systems was found to correlate with the H-bond distances and their strengths, decreasing in the order MA3(DMC)Pb2I7 > MA4(DMC)Pb3I10 > MA2(DMC)PbI4 ∼ MA3(DMC)Pb2Br7. The relatively loosely bound nature of DMC molecules enables us to design a thermochromic cell that can withstand 25 cycles of switching between two colored states. This work exemplifies the unconventional role of the noncharged solvent molecule in templating the 2D perovskite structure.

2.
Nature ; 561(7721): 88-93, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30150772

RESUMEN

The rising demand for radiation detection materials in many applications has led to extensive research on scintillators1-3. The ability of a scintillator to absorb high-energy (kiloelectronvolt-scale) X-ray photons and convert the absorbed energy into low-energy visible photons is critical for applications in radiation exposure monitoring, security inspection, X-ray astronomy and medical radiography4,5. However, conventional scintillators are generally synthesized by crystallization at a high temperature and their radioluminescence is difficult to tune across the visible spectrum. Here we describe experimental investigations of a series of all-inorganic perovskite nanocrystals comprising caesium and lead atoms and their response to X-ray irradiation. These nanocrystal scintillators exhibit strong X-ray absorption and intense radioluminescence at visible wavelengths. Unlike bulk inorganic scintillators, these perovskite nanomaterials are solution-processable at a relatively low temperature and can generate X-ray-induced emissions that are easily tunable across the visible spectrum by tailoring the anionic component of colloidal precursors during their synthesis. These features allow the fabrication of flexible and highly sensitive X-ray detectors with a detection limit of 13 nanograys per second, which is about 400 times lower than typical medical imaging doses. We show that these colour-tunable perovskite nanocrystal scintillators can provide a convenient visualization tool for X-ray radiography, as the associated image can be directly recorded by standard digital cameras. We also demonstrate their direct integration with commercial flat-panel imagers and their utility in examining electronic circuit boards under low-dose X-ray illumination.

3.
BMC Public Health ; 24(1): 2515, 2024 Sep 16.
Artículo en Inglés | MEDLINE | ID: mdl-39285399

RESUMEN

Social isolation and loneliness (SIL) are public health challenges that disproportionally affect individuals who experience structural and socio-economic exclusion. The social and health outcomes of SIL for people with experiences of being unhoused have largely remained unexplored. Yet, there is limited synthesis of literature focused on SIL to appropriately inform policy and targeted social interventions for people with homelessness experience. The aim of this scoping review is to synthesize evidence on SIL among people with lived experience of homelessness and explore how it negatively impacts their wellbeing. We carried out a comprehensive literature search from Medline, Embase, Cochrane Library, PsycINFO, CINAHL, Sociological Abstracts, and Web of Science's Social Sciences Citation Index and Science Citation Index for peer-reviewed studies published between January 1st, 2000 to January 3rd, 2023. Studies went through title, abstract and full-text screening conducted independently by at least two reviewers. Included studies were then analyzed and synthesized to identify the conceptualizations of SIL, measurement tools and approaches, prevalence characterization, and relationship with social and health outcomes. The literature search yielded 5,294 papers after removing duplicate records. Following screening, we retained 27 qualitative studies, 23 quantitative studies and two mixed method studies. SIL was not the primary objective of most of the included articles. The prevalence of SIL among people with homelessness experience varied from 25 to 90% across studies. A range of measurement tools were used to measure SIL making it difficult to compare results across studies. Though the studies reported associations between SIL, health, wellbeing, and substance use, we found substantial gaps in the literature. Most of the quantitative studies were cross-sectional, and only one study used health administrative data to ascertain health outcomes. More studies are needed to better understand SIL among this population and to build evidence for actionable strategies and policies to address its social and health impacts.


Asunto(s)
Personas con Mala Vivienda , Soledad , Aislamiento Social , Humanos , Personas con Mala Vivienda/psicología , Personas con Mala Vivienda/estadística & datos numéricos , Soledad/psicología , Aislamiento Social/psicología
4.
Phys Rev Lett ; 130(10): 106901, 2023 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-36962044

RESUMEN

Lead halide perovskites enjoy a number of remarkable optoelectronic properties. To explain their origin, it is necessary to study how electromagnetic fields interact with these systems. We address this problem here by studying two classical quantities: Faraday rotation and the complex refractive index in a paradigmatic perovskite CH_{3}NH_{3}PbBr_{3} in a broad wavelength range. We find that the minimal coupling of electromagnetic fields to the k·p Hamiltonian is insufficient to describe the observed data even on the qualitative level. To amend this, we demonstrate that there exists a relevant atomic-level coupling between electromagnetic fields and the spin degree of freedom. This spin-electric coupling allows for quantitative description of a number of previous as well as present experimental data. In particular, we use it here to show that the Faraday effect in lead halide perovskites is dominated by the Zeeman splitting of the energy levels and has a substantial beyond-Becquerel contribution. Finally, we present general symmetry-based phenomenological arguments that in the low-energy limit our effective model includes all basis coupling terms to the electromagnetic field in the linear order.

5.
Niger J Clin Pract ; 24(6): 937-942, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-34121744

RESUMEN

AIMS: The objective of this study was to discuss the outcomes of the oncology patients whose PET/CT scans show incidental focal thyroid 18F-FDG uptake. METHODS: This retrospective analysis examined 2575 18F-FDG PET/CT scans from 1803 patients with no known thyroid cancer history. The survival rates were analyzed for patients with and without cytopathological evaluation. RESULTS: Increased metabolic activity of the thyroid was detected in 96 patients. Of those, 72 were diagnosed with a focal uptake of 18F-FDG and 24 subjects had a diffuse uptake. All 72 patients with a focal uptake were referred for ultrasound (US) and fine-needle aspiration cytology (FNAC). Of those patients, 44 were admitted for US and 16 underwent FNAC. The mean SUVmax was 16.0 ± 7.97 for patients with malignant lesions and 3.24 ± 0.88 for patients with benign lesions (p = 0.023). The mortality rate was higher in the patients who were not evaluated with FNAC. CONCLUSION: Patients with incidental focally increased thyroid 18F-FDG accumulation on PET/CT are known to have a high risk of malignancy. These patients require additional diagnostic procedures to distinguish the underlying pathology. However, the clinical condition of these patients will be the primary concern when performing these procedures.


Asunto(s)
Fluorodesoxiglucosa F18 , Neoplasias de la Tiroides , Humanos , Hallazgos Incidentales , Tomografía Computarizada por Tomografía de Emisión de Positrones , Estudios Retrospectivos , Neoplasias de la Tiroides/diagnóstico por imagen
6.
Nano Lett ; 19(6): 3535-3542, 2019 06 12.
Artículo en Inglés | MEDLINE | ID: mdl-31009227

RESUMEN

Semiconductor quantum well structures have been critical to the development of modern photonics and solid-state optoelectronics. Quantum level tunable structures have introduced new transformative device applications and afforded a myriad of groundbreaking studies of fundamental quantum phenomena. However, noncolloidal, III-V compound quantum well structures are limited to traditional semiconductor materials fabricated by stringent epitaxial growth processes. This report introduces artificial multiple quantum wells (MQWs) built from CsPbBr3 perovskite materials using commonly available thermal evaporator systems. These perovskite-based MQWs are spatially aligned on a large-area substrate with multiple stacking and systematic control over well/barrier thicknesses, resulting in tunable optical properties and a carrier confinement effect. The fabricated CsPbBr3 artificial MQWs can be designed to display a variety of photoluminescence (PL) characteristics, such as a PL peak shift commensurate with the well/barrier thickness, multiwavelength emissions from asymmetric quantum wells, the quantum tunneling effect, and long-lived hot-carrier states. These new artificial MQWs pave the way toward widely available semiconductor heterostructures for light-conversion applications that are not restricted by periodicity or a narrow set of dimensions.

7.
Nano Lett ; 17(3): 2021-2027, 2017 03 08.
Artículo en Inglés | MEDLINE | ID: mdl-28145714

RESUMEN

Understanding defect chemistry, particularly ion migration, and its significant effect on the surface's optical and electronic properties is one of the major challenges impeding the development of hybrid perovskite-based devices. Here, using both experimental and theoretical approaches, we demonstrated that the surface layers of the perovskite crystals may acquire a high concentration of positively charged vacancies with the complementary negatively charged halide ions pushed to the surface. This charge separation near the surface generates an electric field that can induce an increase of optical band gap in the surface layers relative to the bulk. We found that the charge separation, electric field, and the amplitude of shift in the bandgap strongly depend on the halides and organic moieties of perovskite crystals. Our findings reveal the peculiarity of surface effects that are currently limiting the applications of perovskite crystals and more importantly explain their origins, thus enabling viable surface passivation strategies to remediate them.

8.
J Fr Ophtalmol ; 47(3): 104015, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38129198

RESUMEN

PURPOSE: To evaluate the retinal, choroidal, and optic disc head microvascular circulation in human immunodeficiency virus (HIV)-infected individuals without retinopathy receiving highly active antiretroviral therapy (HAART) using swept-source optical coherence tomography angiography (SS-OCTA). METHODS: This cross-sectional study included 100 eyes of 100 patients with HIV infection but no HIV-related ocular disease and 108 eyes of 108 age- and sex-matched healthy subjects as the control group. SS-OCTA was used to assess foveal avascular zone (FAZ) area, retinal nerve fiber layer thickness (RNFL), choriocapillaris (CC) flow area, outer retinal (OR) thickness, radial peripapillary capillary (RPC) vessel density (VD), ONH VD, and choroidal thickness. RESULTS: No statistically significant difference was found between the two groups except in the foveal VD of the deep capillary plexus (DCP). The foveal VD of the DCP was lower in the HIV-positive group (P=0.011). The mean FAZ area (mm2), perimeter (mm), and CC flow area (mm) values were higher in the HIV-positive group at statistically significant levels (P=0.021, P=0.02, and P=0.039, respectively). However, no statistically significant differences were found between the two groups concerning the OR flow area, subfoveal choroidal thickness, or the VDs of the RPC or ONH. CONCLUSIONS: This is the first study in the literature to evaluate the microvascular circulation of the ONH in HIV-positive patients. Although retinal and choroidal microvascular circulation decreased in HIV-positive patients receiving HAART treatment, we found no effect on the microvascular circulation of the ONH or RPC microvascular circulation. Our findings suggest that retinochoroidal microvascular circulation is affected in HIV-positive patients over time.


Asunto(s)
Infecciones por VIH , Seropositividad para VIH , Disco Óptico , Humanos , Disco Óptico/diagnóstico por imagen , Tomografía de Coherencia Óptica , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Estudios Transversales , Voluntarios Sanos , Microcirculación , Angiografía , Vasos Retinianos/diagnóstico por imagen , Angiografía con Fluoresceína
9.
Pol J Vet Sci ; 27(1): 85-94, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38511625

RESUMEN

Anaplasmosis and ehrlichiosis are important tick-borne rickettsial diseases of medical and veterinary importance that cause economic losses in livestock. In this study, the prevalence of Anaplasma ovis, Ehrlichia canis and Ehrlichia chaffeensis was investigated in ticks collected from sheep in various farms in Van province, which is located in the Eastern Anatolian Region of Turkey. The ticks used in this study were collected by random sampling in 26 family farm business in 13 districts of Van province. A total of 688 ticks were collected from 88 sheep and 88 tick pools were created. All ticks identified morphologically as Rhipicephalus bursa. Phylogenetic analysis of Chaperonin and 16S rRNA gene sequences confirmed A. ovis, E. canis and E. chaffeensis in this study. Of the 88 tick pools tested, 28.41% (25/88) were positive for at least one pathogen. Anaplasma DNA was detected in five of the 88 pools (5.68%), E. canis DNA was detected in 19 of the 88 pools (21.59%), and E. chaffeensis DNA was detected in one of the 88 pools (1.14%) of R. bursa ticks. To our knowledge, this is the first report describing the presence of A. ovis, E. canis, and E. chaffeensis in R. bursa ticks collected from sheep in Turkey. Further studies are needed to investigate other co-infections in sheep in Turkey.


Asunto(s)
Anaplasma ovis , Ehrlichia chaffeensis , Rhipicephalus , Animales , Ovinos/genética , Rhipicephalus/genética , Ehrlichia chaffeensis/genética , Ehrlichia canis/genética , Anaplasma ovis/genética , Turquía/epidemiología , ARN Ribosómico 16S/genética , Filogenia , ADN
10.
Small Methods ; : e2400666, 2024 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-39344874

RESUMEN

Interfacial modulation utilizing functional materials is proven to be crucial for obtaining high photovoltaic performance in lead halide perovskite solar cells (PSCs). This study investigates, for the first time, the utilization of a pyrene-based sp2 carbon-conjugated covalent organic framework (sp2c-COF) as an interfacial layer in inverted PSCs. Functionalized with cyano (-CN) Lewis base groups, the sp2c-COF exhibits a dual effect, simultaneously passivating both the NiOx and the perovskite layers. Detailed characterization results highlight the role of sp2c-COF in reducing the Ni3+ defect density in NiOx films and forming Lewis acid-base adducts with undercoordinated Pb2+ on the perovskite surfaces, thereby inhibiting interfacial redox reactions and suppressing non-radiative recombination. Moreover, sp2c-COF leads to improved crystallinity of perovskite films. Benefiting from the synergistic effects, sp2c-COF-modified devices delivered a champion efficiency of 17.64%. These findings underscore the potential of sp2c-COF as a functional interface material for PSCs, offering enhanced efficiency and stability. The study contributes to advancing the understanding and application of covalent organic frameworks in photovoltaic technologies.

11.
Cell Mol Biol (Noisy-le-grand) ; 59 Suppl: OL1835-41, 2013 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-23374453

RESUMEN

This study evaluated the protective effect of Panax Ginseng (PG) on bone metabolism in an experimental ovariectomy (OVX) model of osteoporosis in which inflammation was induced by subcutaneous magnesium silicate. The groups were: sham control (Group1, SH), sham+inflammation (Group2, SHinf), OVX (Group3), OVX+inflammation (Group4, OVXinf), OVX+inflammation+PG 100 mg/kg (Group5, OVXinf+PG1), OVX+inflammation+PG 200 mg/kg (Group6, OVXinf+PG2), OVX+PG 100 mg/kg (Group7, OVX+PG1), OVX+PG 200 mg/kg (Group8, OVX+PG1). After the OVX surgery, all the groups were allowed to recover for two months. On the 59th day after the OVX, inflammation was induced in Groups 2, 4, 5, and 6 by subcutaneous injections of magnesium silicate in the back of the animals. Groups 5 and 7 were administered oral PG 100 mg/kg, and Groups 6 and 8 were administered oral PG 200 mg/kg from the 60th to the 80th day. PG 200 mg/kg was able to restore BMD, up to values measured in both the OVX and the SH animals. The levels of OC and OP decreased in OVXinf+PG1 and OVXinf+PG2 groups. The serum levels of TNF­α, IL­1ß, and IL­6 were increased significantly in the OVXinf rats compared with the SH group. The present data showed that PG protected against in the OVX model and in inflammation-induced bone loss rat model.


Asunto(s)
Densidad Ósea/efectos de los fármacos , Osteoporosis/prevención & control , Panax/química , Extractos Vegetales/uso terapéutico , Animales , Huesos/metabolismo , Huesos/patología , Inflamación/inducido químicamente , Inflamación/complicaciones , Silicatos de Magnesio , Masculino , Osteoporosis/etiología , Osteoporosis/metabolismo , Estrés Oxidativo , Fitoterapia , Ratas , Ratas Wistar
12.
Phys Med Biol ; 68(19)2023 09 22.
Artículo en Inglés | MEDLINE | ID: mdl-37735967

RESUMEN

Purpose. Commercial electron FLASH platforms deliver ultra-high dose rate doses at discrete combinations of pulse parameters including pulse width (PW), pulse repetition frequency (PRF) and number of pulses (N), which dictate unique combinations of dose and dose rates. Additionally, collimation, source to surface distance, and airgaps also vary the dose per pulse (DPP). Currently, obtaining pulse parameters for the desired dose and dose rate is a cumbersome manual process involving creating, updating, and looking up values in large spreadsheets for every treatment configuration. This work presents a pulse parameter optimizer application to match intended dose and dose rate precisely and efficiently.Methods. Dose and dose rate calculation methods have been described for a commercial electron FLASH platform. A constrained optimization for the dose and dose rate cost function was modelled as a mixed integer problem in MATLAB (The MathWorks Inc., Version9.13.0 R2022b, Natick, Massachusetts). The beam and machine data required for the application were acquired using GafChromic film and alternating current current transformers (ACCTs). Variables for optimization included DPP for every collimator, PW and PRF measured using ACCT and airgap factors.Results. Using PW, PRF,Nand airgap factors as parameters, a software was created to optimize dose and dose rate, reaching the closest match if exact dose and dose rates are not achievable. Optimization took 20 s or less to converge to results. This software was validated for accuracy of dose calculation and precision in matching prescribed dose and dose rate.Conclusion. A pulse parameter optimization application was built for a commercial electron FLASH platform to increase efficiency in dose, dose rate, and pulse parameter prescription process. Automating this process reduces safety concerns associated with manual look up and calculation of these parameters, especially when many subjects at different doses and dose rates are to be safely managed.


Asunto(s)
Electricidad , Electrones , Humanos , Frecuencia Cardíaca , Programas Informáticos
13.
Microorganisms ; 11(6)2023 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-37374947

RESUMEN

The accumulation of xenobiotic compounds in different environments interrupts the natural ecosystem and induces high toxicity in non-target organisms. Diclofenac is one of the commonly used pharmaceutical drugs that persist in the environment due to its low natural degradation rate and high toxicity. Therefore, this study aimed to isolate potential diclofenac-degrading bacteria, detect the intermediate metabolites formed, and determine the enzyme involved in the degradation process. Four bacterial isolates were selected based on their ability to utilize a high concentration of diclofenac (40 mg/L) as the sole carbon source. The growth conditions for diclofenac degradation were optimized, and bacteria were identified as Pseudomonas aeruginosa (S1), Alcaligenes aquatilis (S2), Achromobacter spanius (S11), and Achromobacter piechaudii (S18). The highest percentage of degradation was recorded (97.79 ± 0.84) after six days of incubation for A. spanius S11, as analyzed by HPLC. To detect and identify biodegradation metabolites, the GC-MS technique was conducted for the most efficient bacterial strains. In all tested isolates, the initial hydroxylation of diclofenac was detected. The cleavage step of the NH bridge between the aromatic rings and the subsequent cleavage of the ring adjacent to or in between the two hydroxyl groups of polyhydroxylated derivatives might be a key step that enables the complete biodegradation of diclofenac by A. piechaudii S18, as well as P. aeruginosa S1. Additionally, the laccase, peroxidase, and dioxygenase enzyme activities of the two Achromobacter strains, as well as P. aeruginosa S1, were tested in the presence and absence of diclofenac. The obtained results from this work are expected to be a useful reference for the development of effective detoxification bioprocesses utilizing bacterial cells as biocatalysts. The complete removal of pharmaceuticals from polluted water will stimulate water reuse, meeting the growing worldwide demand for clean and safe freshwater.

14.
Pol J Vet Sci ; 26(3): 359-366, 2023 09 20.
Artículo en Inglés | MEDLINE | ID: mdl-37727051

RESUMEN

Cryptosporidium spp., and Giardia duodenalis are intestinal protozoan parasites known to infect humans and various animals and cause diarrhea. This study aimed at determining the prevalence and genotype of Cryptosporidium spp. and Giardia duodenalis in sheep in different locations of Siirt province. The fecal material for this study was collected from 500 sheep in different locations of Siirt province, Turkey. Fecal samples obtained from sheep were examined for Cryptosporidium spp. by Kinyoun Acid Fast staining and the Nested PCR method. Microscopic and Nested PCR methods revealed a prevalence of 2.4% (12/500) and 3.6% (18/500), respectively. Sequence analysis revealed the presence of C. ryanae, C. andersoni, and zoonotic C. parvum. In terms of Giardia duodenalis, 8.4% (42/500) and 10.2% (51/500) prevalence was determined using Nativ-Lugol and Nested PCR methods, respectively. Using sequence analysis, zoonotic assemblages A and B as well as assemblages E and D were detected. As a result of this study, both the prevalence of Cryptosporidium spp. and Giardia duodenalis and the presence of species that appear to be host-specific, as well as those known to be zoonotic, were revealed. A large-scale study is needed to understand the impact of these agents on sheep farming and their consequences on human health.


Asunto(s)
Criptosporidiosis , Cryptosporidium , Giardia lamblia , Enfermedades de las Ovejas , Humanos , Animales , Ovinos , Giardia lamblia/genética , Turquía/epidemiología , Criptosporidiosis/epidemiología , Cryptosporidium/genética , Genotipo , Enfermedades de las Ovejas/epidemiología
15.
J Phys Chem Lett ; 14(27): 6309-6314, 2023 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-37405449

RESUMEN

A rotating organic cation and a dynamically disordered soft inorganic cage are the hallmark features of organic-inorganic lead-halide perovskites. Understanding the interplay between these two subsystems is a challenging problem, but it is this coupling that is widely conjectured to be responsible for the unique behavior of photocarriers in these materials. In this work, we use the fact that the polarizability of the organic cation strongly depends on the ambient electrostatic environment to put the molecule forward as a sensitive probe of the local crystal fields inside the lattice cell. We measure the average polarizability of the C/N-H bond stretching mode by means of infrared spectroscopy, which allows us to deduce the character of the motion of the cation molecule, find the magnitude of the local crystal field, and place an estimate on the strength of the hydrogen bond between the hydrogen and halide atoms. Our results pave the way for understanding electric fields in lead-halide perovskites using infrared bond spectroscopy.

16.
Oral Dis ; 18(8): 802-8, 2012 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-22712806

RESUMEN

OBJECTIVE: The aim of conducting this study was to evaluate the effect of zoledronic acid (ZA) on the new bone formation (NBF) after the insertion of a titanium dental implant, which is very popular treatment in dentistry. STUDY DESIGN: Twelve New Zealand white rabbits were used in this study. The rabbits were divided in two groups. ZA was systemically administered to the study group. Titanium implants were placed to the left and right tibias of the rabbits. RESULTS: The data from the ZA group revealed a statistically significant increase in the bone mineral content and the bone mineral density. A non-decalcified histomorphometric examination conducted on the study group revealed a significant increase of NBF and bone-implant contact (BIC) at 2 and 4 weeks. CONCLUSION: A single dose of systemic ZA administration increases the rate of NBF and augments the quality of the bone.


Asunto(s)
Conservadores de la Densidad Ósea/farmacología , Implantes Dentales , Difosfonatos/farmacología , Imidazoles/farmacología , Oseointegración/efectos de los fármacos , Absorciometría de Fotón/métodos , Animales , Densidad Ósea/efectos de los fármacos , Conservadores de la Densidad Ósea/administración & dosificación , Densitometría/métodos , Materiales Dentales/química , Difosfonatos/administración & dosificación , Procesamiento de Imagen Asistido por Computador/métodos , Imidazoles/administración & dosificación , Infusiones Intravenosas , Osteogénesis/efectos de los fármacos , Conejos , Distribución Aleatoria , Tibia/efectos de los fármacos , Tibia/patología , Tibia/cirugía , Factores de Tiempo , Titanio/química , Ácido Zoledrónico
17.
J Fr Ophtalmol ; 45(1): 81-92, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34895760

RESUMEN

PURPOSE: To analyze the macular microvascular (MMV) architecture, radial peripapillary capillary (RPC) network and choriocapillaris using optical coherence tomography angiography (OCT-A) in patients with systemic sclerosis (SSc) without systemic comorbidities. METHODS: The vessel densities (VDs) of the MMV, foveal avascular zone (FAZ) parameters, choriocapillaris flow areas (CCFAs), RPC VDs, and optic nerve head (ONH) parameters were measured by OCT-A. Retinal thickness and subfoveal choroidal thickness (SFCT) were measured by spectral-domain optical coherence tomography (SD-OCT). The SD-OCT and OCT-A measurements of 53 eyes of 30 SSc patients were compared with 61 eyes of 33 healthy controls. RESULTS: In the MMV analysis, a decrease in the VDs of the superficial capillary plexus and an increase in the FAZ area, FAZ perimeter and non-flow area were detected in the SSc group compared to the controls (P=0.007, P=0.001, P=0.029, P=0.018, and P=0.039, respectively). While there was a decrease in SFCT, no change was found in CCFA (P=0.001 and P=0.902, respectively). The RPC analysis revealed a decrease in the VDs of all vessels for the entire area and the intradisc area, as well as the VDs of the small vessels for the intradisc area (P=0.021, P=0.001, and P=0.003, respectively). In the ONH analysis, there was an increase in the C/D area ratios and cup volumes, and a decrease in the rim areas and nasal quadrant retinal nerve fiber layer thickness (P=0.004, P=0.004, P=0.013, and P=0.032, respectively). CONCLUSION: Decreases in RPC and MMV VDs and changes in ONH parameters were found in OCT-A measurements in patients with SSc.


Asunto(s)
Esclerodermia Sistémica , Tomografía de Coherencia Óptica , Coroides/diagnóstico por imagen , Angiografía con Fluoresceína , Humanos , Microvasos/diagnóstico por imagen , Vasos Retinianos/diagnóstico por imagen , Esclerodermia Sistémica/complicaciones , Esclerodermia Sistémica/diagnóstico por imagen
18.
Nat Commun ; 13(1): 3905, 2022 07 07.
Artículo en Inglés | MEDLINE | ID: mdl-35798732

RESUMEN

Whole-cell screening for Mycobacterium tuberculosis (Mtb) inhibitors is complicated by the pathogen's slow growth and biocontainment requirements. Here we present a synthetic biology framework for assaying Mtb drug targets in engineered E. coli. We construct Target Essential Surrogate E. coli (TESEC) in which an essential metabolic enzyme is deleted and replaced with an Mtb-derived functional analog, linking bacterial growth to the activity of the target enzyme. High throughput screening of a TESEC model for Mtb alanine racemase (Alr) revealed benazepril as a targeted inhibitor, a result validated in whole-cell Mtb. In vitro biochemical assays indicated a noncompetitive mechanism unlike that of clinical Alr inhibitors. We establish the scalability of TESEC for drug discovery by characterizing TESEC strains for four additional targets.


Asunto(s)
Alanina Racemasa , Mycobacterium tuberculosis , Alanina Racemasa/química , Alanina Racemasa/metabolismo , Antituberculosos/química , Antituberculosos/farmacología , Descubrimiento de Drogas , Escherichia coli/genética , Escherichia coli/metabolismo , Ensayos Analíticos de Alto Rendimiento , Mycobacterium tuberculosis/metabolismo
19.
Cureus ; 13(12): e20557, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35103136

RESUMEN

BACKGROUND: Rhinoplasty is one of the most challenging esthetic operations as it demands an optimal esthetic and practical outcome. Complications of rhinoplasty may occur intraoperatively or postoperatively during wound healing and contracture. OBJECTIVES: The aim of this study was to assess the complications of septorhinoplasty at King Abdullah Medical City Hospital (KAMCH) and to evaluate the satisfaction scores of the patients and the doctors after primary and revision septorhinoplasty. MATERIALS AND METHODS: In the last five years, 32 out of 425 patients (7.5%) underwent revision septorhinoplasty to correct complications of the previous operations performed at KAMCH. This is a retrospective single descriptive study that included Saudi patients aged 18 years and above who underwent primary and revision septorhinoplasty at KAMCH from January 2015 to March 2020. We reviewed the medical records of the patients to identify postoperative complications. Data were analyzed using SPSS statistical program (versions 7 and 8; SPSS Inc, Chicago). RESULTS: The mean age of the 32 patients who underwent revision septorhinoplasty was 26 ± 8.5 years. Most of the complications involved the nasofrontal angle and the columellolabial angle. Statistically significant improvements in the satisfaction scores of the patients and the doctors were observed before the first surgery, after the first surgery, and after the second surgery (P = 0.000 for each time point). CONCLUSION: The satisfaction levels of the patients and the doctors improve after the second surgery.

20.
Biomed Phys Eng Express ; 8(1)2021 11 23.
Artículo en Inglés | MEDLINE | ID: mdl-34768242

RESUMEN

A 3-D dosimeter fills the need for treatment plan and delivery verification required by every modern radiation-therapy method used today. This report summarizes a proof-of-concept study to develop a water-equivalent solid 3-D dosimeter that is based on novel radiation-hard scintillating material. The active material of the prototype dosimeter is a blend of radiation-hard peroxide-cured polysiloxane plastic doped with scintillating agent P-Terphenyl and wavelength-shifter BisMSB. The prototype detector was tested with 6 MV and 10 MV x-ray beams at Ohio State University's Comprehensive Cancer Center. A 3-D dose distribution was successfully reconstructed by a neural network specifically trained for this prototype. This report summarizes the material production procedure, the material's water equivalency investigation, the design of the prototype dosimeter and its beam tests, as well as the details of the utilized machine learning approach and the reconstructed 3-D dose distributions.


Asunto(s)
Dosímetros de Radiación , Radiometría , Humanos , Aprendizaje Automático , Dosis de Radiación , Agua
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