Prevalence of autism spectrum disorder in mainland china over the past 6 years: a systematic review and meta-analysis.

BACKGROUND: Coupled with its rising prevalence, Autism spectrum disorder (ASD) has become a globally recognized public health concern. Nevertheless, large-scale, multicenter studies that analyze the epidemiology of ASD in China are relatively scarce. METHODS: Literature searches were conducted in PubMed/Medline, Embase, the Cochrane Library, Wanfang Data Knowledge Service Platform, China Biology Medicine database (CBM), China Science and Technology Journal Database (CSTJ), and China National Knowledge Infrastructure (CNKI) to retrieve studies published before April 8, 2023, related to ASD prevalence among children aged 0 to 14 years in mainland China. Meta-analysis was conducted using RevMan 5.2 and Stata 14.0. RESULTS: Twenty-one articles were included. The ASD prevalence among children in mainland China has been 0.7% (95% confidence interval(CI): 0.006-0.008) since 2017. The prevalence of ASD among boys was 1.0% (95% CI: 0.008-0.011), which was significantly higher than that among girls at 0.2% (95% CI: 0.002-0.003), with a statistically significant difference (OR = 3.198, 95% CI: 2.489-4.109, P = 0.000). Among the included studies, 18 reported an ASD prevalence of 0.8% (95% CI: 0.007-0.010), while 3 studies reported an autistic disorder (AD) prevalence of 0.7% (95% CI: 0.006-0.008). The prevalence of autism among urban children was 23.9% (95% CI: 0.149-0.328), and in rural areas, it was 0.7% (95% CI: 0.002-0.013), with no statistically significant difference (OR = 1.342, 95% CI: 0.258-6.975, P = 0.727). Regression analysis showed that factors such as region (P = 0.000), age (P = 0.000), study period (P = 0.000), sample size (P = 0.000), sampling method (P = 0.002), population source (P = 0.000), disease type (P = 0.000), quality score of the study (P = 0.000), and diagnostic criteria (P = 0.000) might have contributed to the heterogeneity in ASD prevalence. CONCLUSION: The prevalence of ASD in China from 2017 to 2023 was 7/1000, showing an upward trend compared to that before 2017 (26.50/10,000). The male-to-female prevalence ratio was 5:1.The overall prevalence remained significantly lower than that reported in foreign countries.

Treadmill exercise exerts a synergistic effect with bone marrow mesenchymal stem cell-derived exosomes on neuronal apoptosis and synaptic-axonal remodeling.

Treadmill exercise and mesenchymal stem cell transplantation are both practical and effective methods for the treatment of cerebral ischemia. However, whether there is a synergistic effect between the two remains unclear. In this study, we established rat models of ischemia/reperfusion injury by occlusion of the middle cerebral artery for 2 hours and reperfusion for 24 hours. Rat models were perfused with bone marrow mesenchymal stem cell-derived exosomes (MSC-exos) via the tail vein and underwent 14 successive days of treadmill exercise. Neurological assessment, histopathology, and immunohistochemistry results revealed decreased neuronal apoptosis and cerebral infarct volume, evident synaptic formation and axonal regeneration, and remarkably recovered neurological function in rats subjected to treadmill exercise and MSC-exos treatment. These effects were superior to those in rats subjected to treadmill exercise or MSC-exos treatment alone. Mechanistically, further investigation revealed that the activation of JNK1/c-Jun signaling pathways regulated neuronal apoptosis and synaptic-axonal remodeling. These findings suggest that treadmill exercise may exhibit a synergistic effect with MSC-exos treatment, which may be related to activation of the JNK1/c-Jun signaling pathway. This study provides novel theoretical evidence for the clinical application of treadmill exercise combined with MSC-exos treatment for ischemic cerebrovascular disease.

Multiport all-logic optical switch based on thermally altered light paths in a multimode waveguide.

A generic multiport optical switch capable of generating all-logic outputs is demonstrated by altering the mode profiles and propagation characteristics in a multimode waveguide through a combination of microheaters. The principles and design rules are introduced. As proof of concept, a 3-bit all-logic switch is fabricated on a polymer waveguide platform. The experimental results are in good agreement with the simulations based on a heat solver and the eigenmode expansion method. The device shows polarization insensitive and colorless operation from 1520 to 1600 nm with an extinction ratio between "On" and "Off" states larger than 11.9 dB in all cases. The maximum heat power is 43.9 mW (for (1, 0, 0) state). The simple, compact, and easily scalable device can be used to construct 1×N and M×N switch networks, showing promising applications in on-chip photonic signal processing and computation.

3D integrated wavelength demultiplexer based on a square-core fiber and dual-layer arrayed waveguide gratings.

We present a 3D integrated wavelength demultiplexer using a square-core fiber (SCF) and matched dual-layer arrayed waveguide gratings (AWGs). The SCF works as a 3D fiber multimode interference device, which splits the input light into symmetric four spots. The spots are then coupled to a pitch-matched 4-waveguide network, each connecting an AWG. Interface waveguides are designed to improve the coupling efficiency between the SCF and the dual-layer chip. The four AWGs are designed with different central wavelengths and a large free spectral range (FSR) of 120 nm. To reach a small and uniform insertion loss among different channels, only the central channels of each AWG are used for demultiplexing. The device is fabricated on a polymer platform. The upper and lower layers of the chip are fabricated using the same photolithography mask but rotated 180° so that 4 different AWG designs can be mapped to a single chip. The measured transmission spectra of the four AWGs cover a bandwidth of 112 nm. The insertion loss variation is smaller than 1.4 dB. The designed device can find applications in fiber optic sensing, communication, and astronomy.

Bone marrow-derived mesenchymal stem cells improve post-ischemia neurological function in rats via the PI3K/AKT/GSK-3ß/CRMP-2 pathway.

BACKGROUND: Transplantation of bone marrow-derived mesenchymal stem cells (BMSCs) is a potential therapy for cerebral ischemia. However, the underlying protective mechanism remains undetermined. Here, we tested the hypothesis that transplantation of BMSCs via intravenous injection can alleviate neurological functional deficits through activating PI3K/AKT signaling pathway after cerebral ischemia in rats. METHODS: A cerebral ischemic rat model was established by the 2 h middle cerebral artery occlusion (MCAO). Twenty-four hours later, BMSCs (1 × 106 in 1 ml PBS) from SD rats were injected into the tail vein. Neurological function was evaluated by modified neurological severity score (mNSS) and modified adhesive removal test before and on d1, d3, d7, d10 and d14 after MCAO. Protein expressions of AKT, GSK-3ß, CRMP-2 and GAP-43 were detected by Western-bolt. NF-200 was detected by immunofluorescence. RESULTS: BMSCs transplantation did not only significantly improve the mNSS score and the adhesive-removal somatosensory test after MCAO, but also increase the density of NF-200 and the expression of p-AKT, pGSK-3ß and GAP-43, while decrease the expression of pCRMP-2. Meanwhile, these effects can be suppressed by LY294002, a specific inhibitor of PI3K/AKT. CONCLUSION: These data suggest that transplantation of BMSCs could promote axon growth and neurological deficit recovery after MCAO, which was associated with activation of PI3K/AKT /GSK-3ß/CRMP-2 signaling pathway.

IL-10 produces a dual effect on OGD-induced neuronal apoptosis of cultured cortical neurons via the NF-κB pathway.

As a classic immunoregulatory cytokine, interleukin-10 (IL-10) can provide in vivo and in vitro neuroprotection respectively during cerebral ischemia and after the oxygen-glucose deprivation (OGD)-induced injury. However, its role in cortical neuronal survival at different post-ischemic phases remains unclear. The current study found that IL-10 had distinct effects on the neuronal apoptosis at different OGD stages: at an early stage after OGD, IL-10 promoted the OGD-induced neuronal apoptosis in the cultured primary cortical neurons by activating p65 subunit, which up-regulated Bax expression and down-regulated Bcl-xL expression; at a late OGD stage, however, it attenuated the OGD-induced neuronal apoptosis by activating c-Rel, which up-regulated Bcl-xL expression and down-regulated Bax expression. The early-stage pro-apoptosis and late-stage anti-apoptosis were both partly abolished by PDTC, an NF-κB inhibitor, and promoted by PMA, an NF-κB activator. The optimal anti-apoptotic effect appeared when the cultured neurons were treated with IL-10 at 9-24 h after OGD. Taken together, our findings suggest that IL-10 exerts a dual effect on the survival of the cultured neurons by activating the NF-κB pathway at different stages after OGD injury and that PMA treatment at a late stage can facilitate the IL-10-conferred neuroprotection against OGD-induced neuronal injury.

Netrin-1 Promotes Synaptic Formation and Axonal Regeneration via JNK1/c-Jun Pathway after the Middle Cerebral Artery Occlusion.

As a secreted axon guidance molecule, Netrin-1 has been documented to be a neuroprotective factor, which can reduce infarct volume, promote angiogenesis and anti-apoptosis after stroke in rodents. However, its role in axonal regeneration and synaptic formation after cerebral ischemic injury, and the related underlying mechanisms remain blurred. In this study, we used Adeno-associated vectors carrying Netrin-1 gene (AAV-NT-1) to up-regulate the expression level of Netrin-1 in rats' brain after middle cerebral artery occlusion (MCAO). We found that the up-regulated level of Netrin-1 and its receptor DCC promoted axonal regeneration and synaptic formation; the overexpression of Netrin-1 activated the JNK1 signaling pathway; these effects were partially reduced when JNK1 signaling pathway was inhibited by SP600125 (JNK specific inhibitor). Taken together, these findings suggest that Netrin-1 can facilitate the synaptic formation and axonal regeneration via the JNK1 signaling pathway after cerebral ischemia, thus promoting the recovery of neural functions.

Compact CWDM interleaver based on an interfering loop containing a one-dimensional Fabry-Perot cavity.

We propose and experimentally demonstrate a compact silicon photonic interleaver based on an interfering loop containing a 1D Fabry-Perot (FP) cavity for coarse wavelength division multiplexing (CWDM) applications. The interleaver consists of a directional coupler and a FP cavity designed to minimize the channel crosstalk. Instead of using an off-chip optical circulator, the reflection light of the interleaver can be separated from the input by placing two identical interleavers in a Mach-Zehnder interferometer (MZI) structure for practical applications. We also study the impacts of fabrication errors of the MZI structure. The fabricated device has a footprint of 64 µm×70 µm and a channel spacing of ∼19 nm. The maximum crosstalk is -16 dB in a wavelength range from 1508 nm to 1590 nm.

Silicon photonic bandpass filter based on apodized subwavelength grating with high suppression ratio and short coupling length.

A compact silicon bandpass filter with high sidelobe suppression is proposed and experimentally demonstrated using an apodized subwavelength grating (SWG) coupler. The device is implemented by placing a SWG waveguide next to a strip waveguide, and apodization is employed with a Gaussian profile to taper the gap between the two waveguides. A high sidelobe suppression ratio of 27 dB can be obtained with a 3-dB bandwidth of 8.8 nm and an insertion loss of 2.5 dB. Owing to the large optical phase mismatch between the two waveguides and the presence of the SWG waveguide, the coupling length of the device is reduced to 100.3 µm. The experimental results validate our proposed apodized-SWG-based contradirectional coupler (contra-DC) as a promising device in suppressing out-of-band components in coarse wavelength division multiplexed (CWDM) optical communication systems.

High-extinction-ratio silicon polarization beam splitter with tolerance to waveguide width and coupling length variations.

We demonstrate a compact silicon polarization beam splitter (PBS) based on grating-assisted contradirectional couplers (GACCs). Over 30-dB extinction ratios and less than 1-dB insertion losses are achieved for both polarizations. The proposed PBS exhibits tolerance in width variation, and the polarization extinction ratios remain higher than 20 dB for both polarizations when the width variation is adjusted from + 10 to -10 nm. Benefiting from the enhanced coupling by the GACCs, the polarization extinction ratio can be kept higher than 15 dB and the insertion loss is lower than 2 dB for both polarizations when the coupling length varies from 30.96 to 13.76 µm.

Wavelength and bandwidth-tunable silicon comb filter based on Sagnac loop mirrors with Mach-Zehnder interferometer couplers.

We propose and experimentally demonstrate a wavelength and bandwidth-tunable comb filter based on silicon Sagnac loop mirrors (SLMs) with Mach-Zehnder interferometer (MZI) couplers. By thermally tuning the MZI couplers in common and differential modes, the phase shift and reflectivity of the SLMs can be changed, respectively, leading to tunable wavelength and bandwidth of the comb filter. The fabricated comb filter has 93 comb lines in the wavelength range from 1535 nm to 1565 nm spaced by ~0.322 nm. The central wavelength can be red-shifted by ~0.462 nm with a tuning efficiency of ~0.019 nm/mW. A continuously tunable bandwidth from 5.88 GHz to 24.89 GHz is also achieved with a differential heating power ranging from 0.00 mW to 0.53 mW.

Analysis of an electro-optic modulator based on a graphene-silicon hybrid 1D photonic crystal nanobeam cavity.

We propose and numerically study an on-chip graphene-silicon hybrid electro-optic (EO) modulator operating at the telecommunication band, which is implemented by a compact 1D photonic crystal nanobeam (PCN) cavity coupled to a bus waveguide with a graphene sheet on top. Through electrically tuning the Fermi level of the graphene, both the quality factor and the resonance wavelength can be significantly changed, thus the in-plane lightwave can be efficiently modulated. Based on finite-difference time-domain (FDTD) simulation results, the proposed modulator can provide a large free spectral range (FSR) of 125.6 nm, a high modulation speed of 133 GHz, and a large modulation depth of ~12.5 dB in a small modal volume, promising a high performance EO modulator for wavelength-division multiplexed (WDM) optical communication systems.

Bottom-up Fabrication of Graphene on Silicon/Silica Substrate via a Facile Soft-hard Template Approach.

In this work, a novel soft-hard template method towards the direct fabrication of graphene films on silicon/silica substrate is developed via a tri-constituent self-assembly route. Using cetyl trimethyl ammonium bromide (CTAB) as a soft template, silica (SiO2) from tetramethoxysilane as a hard template, and pyrene as a carbon source, the self-assembly process allows the formation of a sandwich-like SiO2/CTAB/pyrene composite, which can be further converted to high quantity graphene films with a thickness of ~1 nm and a size of over 5 µm by thermal treatment. The morphology and thickness of the graphene films can be effectively controlled through the adjustment of the ratio of pyrene to CTAB. Furthermore, a high nonlinear refractive index n2 of ~10(-12) m(2) W(-1) is measured from graphene/silica hybrid film, which is six orders of magnitude larger than that of silicon and comparable to the graphene from chemical vapor deposition process.

Correlating interleukin-10 promoter gene polymorphisms with human cerebral infarction onset.

Evidence suggests that interleukin-10 (IL-10) deficiency exacerbates inflammation and worsens the outcome of brain ischemia. In view of the critical role of the single nucleotide polymorphic sites -1082 (A/G) and -819 (C/T) in the promoter region of the IL-10 gene, we hypothesized that they are associated with cerebral infarction morbidity in the Chinese Han population. We genotyped these allelic gene polymorphisms by amplification refractory mutation system-polymerase chain reaction methods in 181 patients with cerebral infarction (cerebral infarction group) and 115 healthy subjects (control group). We identified significant differences in genotype distribution and allele frequency of the IL-10-1082 A/G allele between cerebral infarction and control groups (χ (2) = 6.643, P = 0.010). The IL-10-1082 A allele frequency was significantly higher in the cerebral infarction group (92.3%) than in the control group (86.1%) (P = 0.015). Moreover, cerebral infarction risk of the AA genotype was 2-fold higher than with the AG genotype (OR = 2.031, 95%CI: 1.134-3.637). In addition, AA genotype together with hypertension was the independent risk factor of cerebral infarction (OR = 2.073, 95%CI: 1.278-3.364). No statistical difference in genotype distribution or allele frequency of IL-10-819 C/T was found between cerebral infarction and control groups (P > 0.05). These findings suggest that the IL-10-1082 A/G gene polymorphism is involved in cerebral infarction, and increased A allele frequency is closely associated with occurrence of cerebral infarction.

Compact tunable silicon photonic differential-equation solver for general linear time-invariant systems.

We propose and experimentally demonstrate an all-optical temporal differential-equation solver that can be used to solve ordinary differential equations (ODEs) characterizing general linear time-invariant (LTI) systems. The photonic device implemented by an add-drop microring resonator (MRR) with two tunable interferometric couplers is monolithically integrated on a silicon-on-insulator (SOI) wafer with a compact footprint of ~60 µm × 120 µm. By thermally tuning the phase shifts along the bus arms of the two interferometric couplers, the proposed device is capable of solving first-order ODEs with two variable coefficients. The operation principle is theoretically analyzed, and system testing of solving ODE with tunable coefficients is carried out for 10-Gb/s optical Gaussian-like pulses. The experimental results verify the effectiveness of the fabricated device as a tunable photonic ODE solver.

Photonic generation of microwave frequency shift keying signal using a single-drive Mach-Zehnder modulator.

We propose and experimentally demonstrate a new scheme for photonic generation of microwave frequency shift keying (FSK) signal by employing one single-drive Mach-Zehnder modulator (MZM). In the proposed method, an electrical signal with different radio frequency (RF) amplitudes and direct current (DC) components for bit '0' and bit '1' is generated. After amplification, the signal is fed into a single-drive MZM which is biased at the quadrature and null points of its transmission curve for bit '0' and bit '1', respectively. Due to the different RF amplitudes, a microwave FSK signal can be obtained after photodetection, where the space frequency is the same as the RF frequency and the mark frequency is twice as large as the RF frequency. The feasibility of the proposed scheme is verified by a proof-of-concept experiment. 5/10-GHz and 10/20-GHz microwave FSK signals with different bit rates are successfully demonstrated.

The role of norepinephrine and nitric oxide in activities of rat arginine vasopressin neurons in response to immune challenge.

To explore the potential role of norepinephrine (NE) and nitric oxide (NO) in activities of rat hypothalamus arginine vasopressin (AVP) neurons in response to immune challenge, we observed the effect of prazosin, an antagonist of alpha1-adrenergic receptor, and the specific nitric oxide synthase (NOS) inhibitor N(w)nitro-L-arginine-methylester (L-NAME) on the Fos expression in AVP neurons induced by systemic lipopolysaccharide (LPS) using double immunohistochemistry. Intravenous (i.v.) injection of LPS induced Fos expression in AVP neurons mainly in the hypothalamus paraventricular nucleus (PVN) and in the supraoptic nucleus (SON). The percentage of Fos-positive AVP neurons was dose-dependent. Pretreatment with prazosin (5 mg/kg) effectively suppressed the Fos expression induced by LPS (5 microg/kg), whereas L-NAME (30 mg/kg) did not influence the Fos expression in the AVP neurons induced by LPS (0.25, 0.5, 1, 5 microg/kg). Our results suggest that the activation of central AVP neurons caused by systemic LPS may be mediated by NE through alpha1-adrenergic receptors, but could not be changed by NO.