Organic nanoparticles with tunable size and rigidity by hyperbranching and cross-linking using microemulsion ATRP.

Unlike inorganic nanoparticles, organic nanoparticles (oNPs) offer the advantage of "interior tailorability," thereby enabling the controlled variation of physicochemical characteristics and functionalities, for example, by incorporation of diverse functional small molecules. In this study, a unique inimer-based microemulsion approach is presented to realize oNPs with enhanced control of chemical and mechanical properties by deliberate variation of the degree of hyperbranching or cross-linking. The use of anionic cosurfactants led to oNPs with superior uniformity. Benefitting from the high initiator concentration from inimer and preserved chain-end functionality during atom transfer radical polymerization (ATRP), the capability of oNPs as a multifunctional macroinitiator for the subsequent surface-initiated ATRP was demonstrated. This facilitated the synthesis of densely tethered poly(methyl methacrylate) brush oNPs. Detailed analysis revealed that exceptionally high grafting densities (~1 nm-2) were attributable to multilayer surface grafting from oNPs due to the hyperbranched macromolecular architecture. The ability to control functional attributes along with elastic properties renders this "bottom-up" synthetic strategy of macroinitiator-type oNPs a unique platform for realizing functional materials with a broad spectrum of applications.

Cavity-Enhanced Emission from a Silicon T Center.

Silicon T centers present the promising possibility of generating optically active spin qubits in an all-silicon device. However, these color centers exhibit long excited state lifetimes and a low Debye-Waller factor, making them dim emitters with low efficiency into the zero-phonon line. Nanophotonic cavities can solve this problem by enhancing radiative emission into the zero-phonon line through the Purcell effect. In this work, we demonstrate cavity-enhanced emission from a single T center in a nanophotonic cavity. We achieve a 2 order of magnitude increase in the brightness of the zero-phonon line relative to waveguide-coupled emitters, a 23% collection efficiency from emitter to fiber, and an overall emission efficiency into the zero-phonon line of 63.4%. We also observe a lifetime enhancement of 5, corresponding to a Purcell factor exceeding 18 when correcting for the emission to the phonon sideband. These results pave the way toward efficient spin-photon interfaces in silicon photonics.

E3 ligase BRG3 persulfidation delays tomato ripening by reducing ubiquitination of the repressor WRKY71.

Hydrogen sulfide (H2S) is a gaseous signaling molecule reported to play multiple roles in fruit ripening. However, the molecular mechanisms underlying H2S-mediated delay in fruit ripening remain to be established. Here, the gene encoding a WRKY transcription factor, WRKY71, was identified as substantially upregulated in H2S-treated tomato (Solanum lycopersicum) via transcriptome profiling. The expression of WRKY71 was negatively associated with that of CYANOALANINE SYNTHASE1 (CAS1). Transient and stable genetic modification experiments disclosed that WRKY71 acts as a repressor of the tomato ripening process. CAS1 appears to play an opposite role, based on the finding that the ripening process was delayed in the cas1 mutant and accelerated in CAS1-OE tomatoes. Dual-luciferase reporter assay, yeast one-hybrid, electrophoretic mobility shift assay, and transient transformation experiments showed that WRKY71 bound to the CAS1 promoter and suppressed its activation. Moreover, the persulfidation of WRKY71 enhanced its binding ability to the CAS1 promoter. Data from luciferase complementation and Y2H assays confirmed that WRKY71 interacts with a BOI-related E3 ubiquitin-protein ligase 3 (BRG3) and is ubiquitinated in vitro. Further experiments showed that modification of BRG3 via persulfidation at Cys206 and Cys212 led to reduced ubiquitination activity. Our findings support a model whereby BRG3 undergoes persulfidation at Cys206 and Cys212, leading to reduced ubiquitination activity and decreased interactions with the WRKY71 transcript, with a subsequent increase in binding activity of the persulfidated WRKY71 to the CAS1 promoter, resulting in its transcriptional inhibition and thereby delayed ripening of tomatoes. Our collective findings provide insights into a mechanism of H2S-mediated regulation of tomato fruit ripening.

Ultra-compact and high-performance four-channel coarse wavelength-division (de)multiplexing filters based on cascaded Mach-Zehnder interferometers with Bezier-shape directional couplers.

Using cascaded Mach-Zehnder interferometers (CMZIs) provides an attractive option for realizing coarse wavelength-division (de)multiplexing (CWDM) filters with low losses, low crosstalk, flat tops, and high scalability. However, they usually have large footprints and insufficient fabrication tolerances, due to the inferior performance of conventional directional couplers (DCs) used for MZIs. Here, a four-channel CMZI wavelength-division (de)multiplexer based on novel Bezier-shape DCs with compact footprints, broad bandwidths and decent fabrication tolerances. For the fabricated (de)multiplexer with 20-nm channel spacing, the excess loss is less than 0.5 dB and the crosstalk is lower than -19.5 dB in the 1-dB bandwidth of 12.8 nm. For the case with a core-width deviation of ±20 nm, the device still performs very well with low losses and low crosstalk. Compared to the state-of-the-art MZI-based CWDM filters, the present device has slightly high performances and a footprint of 0.012 mm2 shrunk greatly by ∼3-folds. This work can be extended for more channels and other material platforms.

Thrombospondin-1, CD47, and SIRPα display cell-specific molecular signatures in human islets and pancreata.

Thrombospondin-1 (TSP1) is a secreted protein minimally expressed in health but increased in disease and age. TSP1 binds to the cell membrane receptor CD47, which itself engages signal regulatory protein α (SIRPα), and the latter creates a checkpoint for immune activation. Individuals with cancer administered checkpoint-blocking molecules developed insulin-dependent diabetes. Relevant to this, CD47 blocking antibodies and SIRPα fusion proteins are in clinical trials. We characterized the molecular signature of TSP1, CD47, and SIRPα in human islets and pancreata. Fresh islets and pancreatic tissue from nondiabetic individuals were obtained. The expression of THBS1, CD47, and SIRPA was determined using single-cell mRNA sequencing, immunofluorescence microscopy, Western blot, and flow cytometry. Islets were exposed to diabetes-affiliated inflammatory cytokines and changes in protein expression were determined. CD47 mRNA was expressed in all islet cell types. THBS1 mRNA was restricted primarily to endothelial and mesenchymal cells, whereas SIRPA mRNA was found mostly in macrophages. Immunofluorescence staining showed CD47 protein expressed by ß cells and present in the exocrine pancreas. TSP1 and SIRPα proteins were not seen in islets or the exocrine pancreas. Western blot and flow cytometry confirmed immunofluorescent expression patterns. Importantly, human islets produced substantial quantities of secreted TSP1. Human pancreatic exocrine and endocrine tissue expressed CD47, whereas fresh islets displayed cell surface CD47 and secreted TSP1 at baseline and in inflammation. These findings suggest unexpected effects on islets from agents that intersect TSP1-CD47-SIRPα.NEW & NOTEWORTHY CD47 is a cell surface receptor with two primary ligands, soluble thrombospondin-1 (TSP1) and cell surface signal regulatory protein alpha (SIRPα). Both interactions provide checkpoints for immune cell activity. We determined that fresh human islets display CD47 and secrete TSP1. However, human islet endocrine cells lack SIRPα. These gene signatures are likely important given the increasing use of CD47 and SIRPα blocking molecules in individuals with cancer.

Effect of Imaging Markers on Reperfusion Therapy in Basilar Artery Occlusion.

OBJECTIVE: We aimed to investigate the effectiveness of endovascular therapy (EVT) versus intravenous thrombolysis (IVT) in patients with basilar artery occlusion (BAO), based on the information of advanced imaging. METHODS: We analyzed data of stroke patients with radiologically confirmed BAO within 24 hours. BAO subjects were categorized into "top-of-the-basilar" syndrome (TOBS) and other types. An initial infarct size of <70ml and a ratio of ischemic tissue to infarct volume of ≥1.8 was defined as "target mismatch." The primary outcome was a good outcome, defined as a modified Rankin Scale score of 0 to 3 at 3 months. Propensity score adjustment and inverse probability of treatment weighting (IPTW) propensity score methods were used. RESULTS: Among 474 BAO patients, 93 (19.6%) were treated with IVT prior to EVT, 91 (19.2%) were treated with IVT alone, 95 (20.0%) were treated with EVT alone, and 195 (41.1%) were treated with antithrombotic therapy. In IPTW analyses, we found no benefit of EVT over IVT for good outcome in either TOBS patients (odds ratio = 1.08, 95% confidence interval [CI] = 0.88-1.31) or those with other types (odds ratio = 1.13, 95% CI = 0.94-1.36). However, in patients with other types, if there existed a target mismatch, EVT was independently related to good outcome (odds ratio = 1.46, 95% CI = 1.17-1.81). INTERPRETATION: The "target mismatch profile" seems to be a possible candidate selection standard of EVT for those with other types of BAO. Future studies should separate TOBS from other types of BAO, and try to use advanced imaging. ANN NEUROL 2022;92:97-106.

Hybrid Si-GaAs photonic crystal cavity for lasing and bistability.

The heterogeneous integration of silicon with III-V materials provides a way to overcome silicon's limited optical properties toward a broad range of photonic applications. Hybrid modes are a promising way to integrate such heterogeneous Si/III-V devices, but it remains unclear how to utilize these modes to achieve photonic crystal cavities. Herein, using 3D finite-difference time-domain simulations, we propose a hybrid Si-GaAs photonic crystal cavity design that operates at telecom wavelengths and can be fabricated without requiring careful alignment. The hybrid cavity consists of a patterned silicon waveguide that is coupled to a wider GaAs slab featuring InAs quantum dots. We show that by changing the width of the silicon cavity waveguide, we can engineer the hybrid modes and control the degree of coupling to the active material in the GaAs slab. This provides the ability to tune the cavity quality factor while balancing the device's optical gain and nonlinearity. With this design, we demonstrate cavity mode confinement in the GaAs slab without directly patterning it, enabling strong interaction with the embedded quantum dots for applications such as low-power-threshold lasing and optical bistability (156 nW and 18.1 µW, respectively). This heterogeneous integration of an active III-V material with silicon via a hybrid cavity design suggests a promising approach for achieving on-chip light generation and low-power nonlinear platforms.

High-performance and compact integrated photonic dichroic filters and triplexer realized by an efficient inverse design.

Integrated optical filters are key components in various photonic integrated circuits for applications of communication, spectroscopy, etc. The dichroic filters can be flexibly cascaded to construct filters with various channel numbers and bandwidths. Therefore, the development of high-performance and compact dichroic filters is crucial. In this work, we develop the dichroic filters with 1.49/1.55-µm channels by an inverse design. Benefiting from a search-space-dimension control strategy and advanced optimization algorithm, our efficient design method results in two high-performance dichroic filters without and with subwavelength gratings (SWGs). The comparison suggests that SWGs in filters can be useful for loss reduction and footprint compression by dispersion engineering. The developed dichroic filter with SWGs exhibits measured bandwidths of 26/29 nm, excess losses of < 0.5 dB, and crosstalks of <-10 dB with a compact footprint of 2.5 × 22.0 µm2. It has advantages in performance or compactness compared to the previously reported counterparts. A triplexer with a footprint of 10.5 × 117 µm2 is developed based on the dichroic filters, also showing decent overall performance and compactness.

Expression levels of serine proteases, their homologs, and prophenoloxidase in the Eriocheir sinensis with hepatopancreatic necrosis syndrome (HPNS) and their expression regulation by Runt.

The occurrence of hepatopancreatic necrosis syndrome (HPNS) has seriously affected the sustainable development of Chinese mitten crab (Eriocheir sinensis) farming industry. Limited studies have focused on the immune responses in crabs with HPNS. Serine proteases (SPs) and SP homologs (SPHs) play important roles in the innate immunity of crustaceans. This study investigated the effects of HPNS on the expression levels of genes related to prophenoloxidase (proPO) activation system, and the relationship between Runt transcription factor and the transcriptions of these genes. Eight SPs and five SPHs (SPH1-4, Mas) were identified from E. sinensis. SPs contain a catalytic triad of "HDS", while SPHs lack a catalytic residue. SPs and SPHs all contain a conservative Tryp_SPc domain. Evolutionary analysis showed that EsSPs, EsSPHs, EsPO, and EsRunt were clustered with SPs, SPHs, POs, and Runts of other arthropods, respectively. In crabs with HPNS, the expression levels of six SPs (1, 3, 4, 6, 7, and 8), five SPHs, and PO were significantly upregulated in the hepatopancreas. The knockdown of EsRunt could evidently decrease the expression levels of four SPs (3, 4, 5 and 8), five SPHs (SPH1-4, Mas), and PO. Therefore, the occurrence of HPNS activates the proPO system. Furthermore, the expression levels of partial genes related to proPO system were regulated by Runt. The activation of innate immune system may be a strategy for crabs with HPNS to improve immunity and fight diseases. Our study provides a new understanding of the relationship between HPNS and innate immunity.

Characteristics of preoperative atrial fibrillation in geriatric patients with hip fracture and construction of a clinical prediction model: a retrospective cohort study.

INTRODUCTION: Atrial fibrillation is the most common atrial arrhythmia in the perioperative period and is associated with prolonged hospital stay, increased costs, and increased mortality. However, there are few data on the predictors and incidence of preoperative atrial fibrillation in hip fracture patients. Our aim was to identify predictors of preoperative atrial fibrillation and to propose a valid clinical prediction model. METHODS: Predictor variables included demographic and clinical variables. LASSO regression analyzes were performed to identify predictors of preoperative atrial fibrillation, and models were constructed and presented as nomograms. Area under the curve, calibration curve, and decision curve analysis (DCA) were used to examine the discriminative power, calibration, and clinical efficacy of the predictive models. Bootstrapping was used for validation. RESULTS: A total of 1415 elderly patients with hip fractures were analyzed. Overall, 7.1% of patients had preoperative atrial fibrillation, and they were at significant risk for thromboembolic events. Patients with preoperative AF had a significantly longer delay in surgery than those without preoperative atrial fibrillation (p < 0.05). Predictors for preoperative atrial fibrillation were hypertension (OR 1.784, 95% CI 1.136-2.802, p < 0.05), C-reactive protein at admission (OR 1.329, 95% CI 1.048-1.662, p < 0.05), systemic inflammatory response index at admission (OR 2.137, 95% CI, 1.678-2.721 p < 0.05), Age-Adjusted Charlson Comorbidity Index (OR 1.542, 95% CI 1.326-1.794, p < 0.05), low potassium(OR 2.538, 95% CI 1.623-3.968, p < 0.05), anemia(OR 1.542, 95% CI 1.326-1.794, p < 0.05). Good discrimination and calibration effect of the model was showed. Interval validation could still achieve the C-index value of 0.799. DCA demonstrated this nomogram has good clinical utility. CONCLUSION: This model has a good predictive effect on preoperative atrial fibrillation in elderly patients with hip fractures, which can help to better plan clinical evaluation.