Publications by authors named "Jack Hu"

Metasurfaces precisely control the amplitude, polarization and phase of light, with applications spanning imaging, sensing, modulation and computing. Three crucial performance metrics of metasurfaces and their constituent resonators are the quality factor (Q factor), mode volume (V) and ability to control far-field radiation. Often, resonators face a trade-off between these parameters: a reduction in V leads to an equivalent reduction in Q, albeit with more control over radiation.

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Unlike coding genes, the number of lncRNA genes in organism genomes is relatively proportional to organism complexity. From plants to humans, the tissues with highest numbers and levels of lncRNA gene expression are the male reproductive organs. To learn why, we initiated a genome-wide analysis of Drosophila lncRNA spatial expression patterns in these tissues.

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Genetic analysis methods are foundational to advancing personalized medicine, accelerating disease diagnostics, and monitoring the health of organisms and ecosystems. Current nucleic acid technologies such as polymerase chain reaction (PCR) and next-generation sequencing (NGS) rely on sample amplification and can suffer from inhibition. Here, we introduce a label-free genetic screening platform based on high quality (high-Q) factor silicon nanoantennas functionalized with nucleic acid fragments.

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Excitons in two-dimensional transition metal dichalcogenides have a valley degree of freedom that can be optically manipulated for quantum information processing. Here, we integrate MoS monolayers with achiral silicon disk array metasurfaces to enhance and control valley-specific absorption and emission. Through the coupling to the metasurface electric and magnetic Mie modes, the intensity and lifetime of the emission of neutral excitons, trions, and defect bound excitons can be enhanced and shortened, respectively, while the spectral shape can be modified.

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Optical metasurfaces offer unprecedented flexibility in light wave manipulation but suffer weak resonant enhancement. Tackling this problem, we experimentally unveil a new phase gradient metasurface platform made entirely from individually addressable high quality factor (high-) silicon meta-atoms. Composed of pairs of nearly identical nanoblocks, these meta-atoms support dipolar-guided-mode resonances that, due to the controlled suppression of radiation loss, serve as highly sensitive phase pixels when placed above a mirror.

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Objectives: To describe ovulation inhibition and safety of daily oral ulipristal acetate (UPA) over 84 days.

Study Design: This multi-center phase 1 and/or 2 trial randomized participants to use oral ulipristal 10 mg or 5 mg daily or a 3 cycle regimen of 5 mg for 24 days followed by four placebo days. We stratified randomization by body mass index (BMI) <32 or 32-40 kg/m.

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Objectives: To determine the incidence of out-of-range segesterone acetate (NES) concentrations in participants of a pharmacokinetic/pharmacodynamic trial of a continuous use contraceptive vaginal ring (CVR) releasing NES and estradiol (E2). We hypothesized that out-of-range concentrations reflect nonadherent ring use and predict ovulation risk.

Study Design: We conducted a secondary analysis of data from a prospective, multi-centered, randomized, Phase IIa dose-finding trial for a CVR releasing NES and E2.

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OCCUPATIONAL APPLICATIONSMotion analysis of three workers at a large hospital kitchen was conducted using video recordings as part of this case study. Workers were observed during both a high-demand period and a low-demand period to evaluate their exposure to physical risk factors for work-related musculoskeletal disorders. On average, workers' reaching posture did not change significantly with customer demand.

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Article Synopsis
  • Genetic analysis methods are crucial for enhancing personalized medicine, speeding up disease diagnostics, and monitoring health in organisms and ecosystems.
  • Current nucleic acid technologies require sample amplification, which increases processing time and costs, making them less efficient.
  • The new label-free screening platform using high-Q silicon nanoantennas allows for rapid, high specificity detection of genetic sequences, enabling simultaneous analysis of multiple targets without the need for amplification.
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Strong enhancement of molecular circular dichroism (CD) has the potential to enable efficient asymmetric photolysis, a method of chiral separation that has conventionally been impeded by insufficient yield and low enantiomeric excess. Here, we study experimentally how predicted enhancements in optical chirality density near resonant silicon nanodisks boost CD. We use fluorescence-detected circular dichroism (FDCD) spectroscopy to measure indirectly the differential absorption of circularly polarized light by a monolayer of optically active molecules functionalized to silicon nanodisk arrays.

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Background: In 2017, the Addendum Guidelines for the Prevention of Peanut Allergy were published with recommendations on early introduction of peanut-containing foods based on infants' clinical history.

Objective: We sought to conduct a nationwide US survey to assess Guidelines implementation among allergists and immunologists who manage infants for food allergy.

Methods: Survey invitations were delivered to 3281 nonretired, US members of the American Academy of Asthma, Allergy & Immunology, board certified in allergy and immunology.

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Importance: The 2017 Addendum Guidelines for the Prevention of Peanut Allergy in the United States recommend that pediatricians assess infant peanut allergy risk and introduce peanut in the diet at age 4 to 6 months. Early introduction has the potential to prevent peanut allergy development.

Objectives: To measure the rates of guideline awareness and implementation and to identify barriers to and factors associated with implementation among US pediatricians.

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Serum IL-6 was associated with asthma exacerbation risk but not with symptoms or lung function in urban children; further studies to evaluate the role of IL-6 in the life course of asthma are needed.

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We have investigated the relationship between the function of the gene (), which is the Drosophila homolog of (), and the EGFR signaling pathway. We report that mutant embryos are defective in EGFR signaling dependent processes, namely chordotonal organ recruitment and oenocyte specification. We also show the temperature sensitive hypomorphic allele is enhanced by the hypomorphic MAPK allele ( ).

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The phenomenon of the cytoplasmic localisation of mitochondrial ribosomal subunits (12 S mitochondrial rRNA and 16 S mitochondrial rRNA) has been discovered by scientific teams working with spermatogenic cells of mice. Previous reports showed that the release of mitochondrial substance occurs during interaction of mitochondria with the germ plasm granules (GG). To determine if the interplay between the vasa-positive GG and the mitochondria is associated with cytoplasmic localisation of mtrRNAs, we studied the spermatogenic cells of zebrafish, Danio rerio.

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Article Synopsis
  • Rhinitis is highly prevalent in urban children with asthma, affecting 93.5% of a studied group, with perennial allergic rhinitis being the most common and severe type.
  • The study analyzed 619 children and found that many remained symptomatic despite treatment, especially those with difficult-to-control asthma.
  • The findings suggest that rhinitis and asthma are closely linked, representing two manifestations of the same underlying airway condition.
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Background: Atopic dermatitis (AD) is a common inflammatory skin disease. A subset of patients with AD are susceptible to disseminated herpes simplex virus (HSV) infection, a complication termed eczema herpeticum (ADEH+). The immune mechanisms causing ADEH+ remain elusive.

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In our efforts to determine the patterns of expression and subcellular localization of Drosophila RNAs on a genome-wide basis, and in a variety of tissues, we have developed numerous modifications and improvements to our original fluorescent in situ hybridization (FISH) protocol. To facilitate throughput and cost effectiveness, all steps, from probe generation to signal detection, are performed using exon 96-well microtiter plates. Digoxygenin (DIG)-labelled antisense RNA probes are produced using either cDNA clones or genomic DNA as templates.

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In a previous analysis of 2300 mRNAs via whole-mount fluorescent in situ hybridization in cellularizing Drosophila embryos, we found that 70% of the transcripts exhibited some form of subcellular localization. To see whether this prevalence is unique to early Drosophila embryos, we examined ∼8000 transcripts over the full course of embryogenesis and ∼800 transcripts in late third instar larval tissues. The numbers and varieties of new subcellular localization patterns are both striking and revealing.

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Synaptic transmission is highly plastic and subject to regulation by a wide variety of neuromodulators and neuropeptides. In the present study, we have examined the role of isoforms of the cytochrome b561 homologue called no extended memory (nemy) in regulation of synaptic strength and plasticity at the neuromuscular junction (NMJ) of third instar larvae in Drosophila. Specifically, we generated two independent excisions of nemy that differentially affect the expression of nemy isoforms.

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Germline cells segregate from the soma to maintain their totipotency, but the cellular mechanisms of this segregation are unclear. The Drosophila melanogaster embryo forms a posterior group of primordial germline cells (PGCs) by their division from the syncytial soma. Extended plasma membrane furrows enclose the PGCs in response to the germ plasm protein Germ cell-less (Gcl) and Rho1-actomyosin activity.

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Previous work has shown that many of the 18 family members of Drosophila nuclear receptor transcription factors function in a temporal hierarchy to coordinate developmental progression and growth with the rate limiting process of metabolism. To gain further insight into these interactions and processes, we have undertaken a whole-family analysis of nuclear receptor mRNA spatial expression patterns over the entire process of embryogenesis, as well as the 3rd instar wandering larva stage, by using high-resolution fluorescence in situ hybridization. Overall, the patterns of expression are remarkably consistent with previously mapped spatial activity profiles documented during the same time points, with similar hot spots and temporal profiles in endocrine and metabolically important tissues.

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We present a novel self-templating strategy for directly fabricating monodisperse hollow polymer microspheres (HPMs) from vinyl-containing organosilica microspheres (VOMs) through a polymer-backbone-transition method (PBTM). The VOMs play the roles of both templates and precursors in the new shells. The uniform HPMs with varying sizes from 320 nm to 1.

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An ultrafast, facile, and efficient microwave hydrothermal approach was designed to fabricate magnetic Fe(3)O(4)/phenol-formaldehyde (PF) core-shell microspheres for the first time. The structure of the Fe(3)O(4)/PF core-shell microspheres could be well controlled by the in situ polycondensation of phenol and formaldehyde with magnetic Fe(3)O(4) clusters as the seeds in an aqueous solution without any surfactants. The effect of synthetic parameters, such as the feeding amounts of phenol, the dosages of formaldehyde, the reaction temperatures, and the microwave heating time, on the morphologies and sizes of the Fe(3)O(4)/PF microspheres were investigated in details.

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An effective method was developed for synthesizing magnetite/polymer colloidal composite microspheres with controllable variations in size and shape of the nanostructures and desirable interfacial chemical functionalities, using surfactant-free seeded emulsion polymerization with magnetite (Fe(3)O(4)) colloidal nanocrystal clusters (CNCs) as the seed, styrene (St) as the monomer, and potassium persulfate (KPS) as the initiator. The sub-micrometer-sized citrate-acid-stabilized Fe(3)O(4) CNCs were first obtained via ethylene glycol (EG)-mediated solvothermal synthesis, followed by 3-(trimethoxysilyl)propyl methacrylate (MPS) modification to immobilize the active vinyl groups onto the surfaces, and then the hydrophobic St monomers were polymerized at the interfaces to form the polymer shells by seeded emulsion radical polymerization. The morphology of the composite microspheres could be controlled from raspberry- and flower-like shapes, to eccentric structures by simply adjusting the feeding weight ratio of the seed to the monomer (Fe(3)O(4)/St) and varying the amount of cross-linker divinyl benzene (DVB).

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