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2.
Ann Med Surg (Lond) ; 86(4): 2124-2129, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38576981

ABSTRACT

Introduction: Surgical complications in younger patients can lead to infections, delayed healing, prolonged hospital stays, and other negative outcomes, significantly affecting their recovery. This study explores the potential impact of breastfeeding on mitigating these complications, aiming to enhance our understanding of postoperative care for paediatric and adolescent patients. Methodology: The authors conducted a systematic search on databases such as PubMed, Scopus, Web of Science, and EMBASE, using relevant MESH keywords, adhering to the "Preferred Reporting Items for Systematic Reviews and Meta-analysis" methodology. Quality assessments were performed, and studies scoring above 70% were included for standardized data incorporation. Data extraction followed Cochrane Consumers and Communication Review group's guidelines. Bias and ethical criteria were considered and provided valuable evidence to answer the research question. Results: Among 402 initially reviewed articles, six met inclusion criteria: 3 observational cohort studies, 2 systematic reviews, and 1 randomized controlled trial. The selected literature consistently demonstrates a significant reduction in postoperative infection rates and improved outcomes. Breastfeeding shortened postoperative hospital stays, accelerated recovery, and enhanced nutritional status, potentially reducing healthcare resource utilization and patient financial burden. Lower mortality and morbidity rates were also observed. Conclusion: This systematic review provides compelling evidence of breastfeeding's positive impact on surgical outcomes in the paediatric population. While the authors' findings support the benefits of breastfeeding in this age group, further large-scale, multicenter research is needed to provide stronger evidence for guiding clinical practices.

4.
Nano Lett ; 23(5): 1680-1687, 2023 Mar 08.
Article in English | MEDLINE | ID: mdl-36728762

ABSTRACT

High efficiency micro-LEDs, with lateral dimensions as small as one micrometer, are desired for next-generation displays, virtual/augmented reality, and ultrahigh-speed optical interconnects. The efficiency of quantum well LEDs, however, is reduced to negligibly small values when scaled to such small dimensions. Here, we show such a fundamental challenge can be overcome by developing nanowire excitonic LEDs. Harnessing the large exciton oscillator strength of quantum-confined nanostructures, we demonstrate a submicron scale green-emitting LED having an external quantum efficiency and wall-plug efficiency of 25.2% and 20.7%, respectively, the highest values reported for any LEDs of this size to our knowledge. We established critical factors for achieving excitonic micro-LEDs, including the epitaxy of nanostructures to achieve strain relaxation, the utilization of semipolar planes to minimize polarization effects, and the formation of nanoscale quantum-confinement to enhance electron-hole wave function overlap. This work provides a viable path to break the efficiency bottleneck of nanoscale optoelectronics.

5.
ACS Synth Biol ; 12(2): 511-523, 2023 02 17.
Article in English | MEDLINE | ID: mdl-36715625

ABSTRACT

We present a full-stack modeling, analysis, and parameter identification pipeline to guide the modeling and design of biological systems starting from specifications to circuit implementations and parametrizations. We demonstrate this pipeline by characterizing the integrase and excisionase activity in a cell-free protein expression system. We build on existing Python tools─BioCRNpyler, AutoReduce, and Bioscrape─to create this pipeline. For enzyme-mediated DNA recombination in a cell-free system, we create detailed chemical reaction network models from simple high-level descriptions of the biological circuits and their context using BioCRNpyler. We use Bioscrape to show that the output of the detailed model is sensitive to many parameters. However, parameter identification is infeasible for this high-dimensional model; hence, we use AutoReduce to automatically obtain reduced models that have fewer parameters. This results in a hierarchy of reduced models under different assumptions to finally arrive at a minimal ODE model for each circuit. Then, we run sensitivity analysis-guided Bayesian inference using Bioscrape for each circuit to identify the model parameters. This process allows us to quantify integrase and excisionase activity in cell extracts enabling complex-circuit designs that depend on accurate control over protein expression levels through DNA recombination. The automated pipeline presented in this paper opens up a new approach to complex circuit design, modeling, reduction, and parametrization.


Subject(s)
DNA , Integrases , Integrases/genetics , Bayes Theorem , Cell-Free System
6.
Light Sci Appl ; 11(1): 294, 2022 Oct 10.
Article in English | MEDLINE | ID: mdl-36216825

ABSTRACT

Micro or submicron scale light-emitting diodes (µLEDs) have been extensively studied recently as the next-generation display technology. It is desired that µLEDs exhibit high stability and efficiency, submicron pixel size, and potential monolithic integration with Si-based complementary metal-oxide-semiconductor (CMOS) electronics. Achieving such µLEDs, however, has remained a daunting challenge. The polar nature of III-nitrides causes severe wavelength/color instability with varying carrier concentrations in the active region. The etching-induced surface damages and poor material quality of high indium composition InGaN quantum wells (QWs) severely deteriorate the performance of µLEDs, particularly those emitting in the green/red wavelength. Here we report, for the first time, µLEDs grown directly on Si with submicron lateral dimensions. The µLEDs feature ultra-stable, bright green emission with negligible quantum-confined Stark effect (QCSE). Detailed elemental mapping and numerical calculations show that the QCSE is screened by introducing polarization doping in the active region, which consists of InGaN/AlGaN QWs surrounded by an AlGaN/GaN shell with a negative Al composition gradient along the c-axis. In comparison with conventional GaN barriers, AlGaN barriers are shown to effectively compensate for the tensile strain within the active region, which significantly reduces the strain distribution and results in enhanced indium incorporation without compromising the material quality. This study provides new insights and a viable path for the design, fabrication, and integration of high-performance µLEDs on Si for a broad range of applications in on-chip optical communication and emerging augmented reality/mixed reality devices, and so on.

7.
PLoS Comput Biol ; 18(4): e1009987, 2022 04.
Article in English | MEDLINE | ID: mdl-35442944

ABSTRACT

Biochemical interactions in systems and synthetic biology are often modeled with chemical reaction networks (CRNs). CRNs provide a principled modeling environment capable of expressing a huge range of biochemical processes. In this paper, we present a software toolbox, written in Python, that compiles high-level design specifications represented using a modular library of biochemical parts, mechanisms, and contexts to CRN implementations. This compilation process offers four advantages. First, the building of the actual CRN representation is automatic and outputs Systems Biology Markup Language (SBML) models compatible with numerous simulators. Second, a library of modular biochemical components allows for different architectures and implementations of biochemical circuits to be represented succinctly with design choices propagated throughout the underlying CRN automatically. This prevents the often occurring mismatch between high-level designs and model dynamics. Third, high-level design specification can be embedded into diverse biomolecular environments, such as cell-free extracts and in vivo milieus. Finally, our software toolbox has a parameter database, which allows users to rapidly prototype large models using very few parameters which can be customized later. By using BioCRNpyler, users ranging from expert modelers to novice script-writers can easily build, manage, and explore sophisticated biochemical models using diverse biochemical implementations, environments, and modeling assumptions.


Subject(s)
Biochemical Phenomena , Programming Languages , Models, Biological , Software , Synthetic Biology , Systems Biology
8.
Adv Mater ; 34(21): e2201387, 2022 May.
Article in English | MEDLINE | ID: mdl-35355349

ABSTRACT

Monolayer hexagonal boron nitride (hBN) has been widely considered a fundamental building block for 2D heterostructures and devices. However, the controlled and scalable synthesis of hBN and its 2D heterostructures has remained a daunting challenge. Here, an hBN/graphene (hBN/G) interface-mediated growth process for the controlled synthesis of high-quality monolayer hBN is proposed and further demonstrated. It is discovered that the in-plane hBN/G interface can be precisely controlled, enabling the scalable epitaxy of unidirectional monolayer hBN on graphene, which exhibits a uniform moiré superlattice consistent with single-domain hBN, aligned to the underlying graphene lattice. Furthermore, it is identified that the deep-ultraviolet emission at 6.12 eV stems from the 1s-exciton state of monolayer hBN with a giant renormalized direct bandgap on graphene. This work provides a viable path for the controlled synthesis of ultraclean, wafer-scale, atomically ordered 2D quantum materials, as well as the fabrication of 2D quantum electronic and optoelectronic devices.

9.
Ann Med Surg (Lond) ; 62: 76-79, 2021 Feb.
Article in English | MEDLINE | ID: mdl-33505675

ABSTRACT

Global outbreak of the corona virus disease 2019 (COVID19) has not only challenged the existing healthcare systems but is also a threat to the world economy and stability. In the recent times the world has seen the best healthcare systems collapsing due to the overwhelming burden. Thus, it shows that there have been major lacunae in the pandemic preparedness across the globe. Hence, there is an urgent need to identify the problems, learn from failures and to prepare for future pandemics to reduce the loss of lives and livelihood. In the modern era, blend of public healthcare systems, medical sciences and technology can be put to use to provide solutions. In this article, the authors propose a developmental model of international integrated database software which would connect all the players involved in the management of a pandemic. Better networking and warning system is a key to successful containment of a new viral outbreak.

10.
Opt Express ; 27(26): 38413-38420, 2019 Dec 23.
Article in English | MEDLINE | ID: mdl-31878609

ABSTRACT

We report on the demonstration of top emitting AlGaN tunnel junction deep ultraviolet (UV) light emitting didoes (LEDs) operating at ∼267 nm. We show, both theoretically and experimentally, that the light extraction efficiency can be enhanced by nearly a factor of two with the incorporation of AlGaN nanowire photonic crystal structures. A peak wall-plug efficiency (WPE) ∼3.5% and external quantum efficiency (EQE) ∼5.4% were measured for AlGaN LEDs directly on-wafer without any packaging. This work demonstrates a viable path for achieving high efficiency deep UV LEDs through the integration of AlGaN planar and nanoscale structures.

11.
Opt Lett ; 44(23): 5679-5682, 2019 Dec 01.
Article in English | MEDLINE | ID: mdl-31774752

ABSTRACT

Aluminum-nitride-on-sapphire has recently emerged as a novel low-loss photonics platform for a variety of on-chip electro-optics as well as linear and nonlinear optics applications. In this Letter, we demonstrate ultrahigh quality factor (Qint) microring resonators using single-crystal aluminum nitride grown on a sapphire substrate with an optimized design and fabrication process. A record high intrinsic Qint up to 2.8×106 at the wavelength of 1550 nm is achieved with a fully etched structure, indicating a low propagation loss less than 0.13 dB/cm. Such high Qint aluminum-nitride-on-sapphire resonators with their wide bandgap and electro-optical and nonlinear optical properties is promising for a wide range of low-power and high-power compact on-chip applications over a broad spectral range.

12.
Nano Lett ; 19(11): 7852-7858, 2019 11 13.
Article in English | MEDLINE | ID: mdl-31573819

ABSTRACT

We present experimental results confirming extreme quantum confinement in GaN/AlxGa1-xN (x = 0.65 and 1.0) nanowire and planar heterostructures, where the GaN layer thickness is of the order of a monolayer. The results were obtained from temperature- and excitation-dependent and time-resolved photoluminescence measurements. In the GaN/AlN nanowire heterostructure array sample, the measured emission peak at 300 K is ∼5.18-5.28 eV. This is in excellent agreement with the calculated optical gap of 5.23 eV and 160-260 meV below the calculated electronic gap of 5.44 eV, suggesting that the observed emission is excitonic in nature with an exciton binding energy of ∼160-260 meV. Similarly, in the monolayer GaN/Al0.65Ga0.35N planar heterostructure, the measured emission peak at 300 K is 4.785 eV and in good agreement with the calculated optical gap of 4.68 eV and 95 meV below the calculated electronic gap of 4.88 eV. The estimated exciton binding energy is 95 meV and in close agreement with our theoretical calculations. Excitation-dependent and time-resolved photoluminescence data support the presence of excitonic transitions. Our results indicate that deep-ultraviolet excitonic light sources and microcavity devices can be realized with heterostructures incorporating monolayer-thick GaN.

13.
ACS Appl Mater Interfaces ; 11(17): 15457-15466, 2019 May 01.
Article in English | MEDLINE | ID: mdl-30964262

ABSTRACT

Tantalum nitride is a promising photoanode material for solar water splitting, but further study and practical use are constrained by the harsh conditions of the synthesis from Ta metal. Here, we report the direct deposition of crystalline Ta3N5 on fluorine-doped tin oxide (FTO) substrate via a custom-built atomic layer deposition (ALD) system. A combination of TaCl5 (Ta precursor) and ammonia (N source) was sequentially pulsed into the ALD reactor with the substrate heated to 550 °C to deposit compact and thin films of Ta3N5 with controllable thicknesses on FTO substrates. Importantly, it is shown that the FTO is chemically and structurally stable under the reducing conditions of ammonia at 550 °C. These electrodes produced an exceptional photocurrent onset potential of ∼0.3 V versus reversible hydrogen electrode (RHE) with a maximum photocurrent of ∼2.4 mA cm-2 at 1.23 V versus RHE. Results of photoelectrochemical investigations as a function of film thickness and illumination direction reveal that the performance of Ta3N5 is controlled by a hole diffusion length of ∼50 nm. These results are crucial for the successful integration of Ta3N5 in efficient unassisted water-splitting applications.

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