LINC00894 Regulates Cerebral Ischemia/Reperfusion Injury by Stabilizing EIF5 and Facilitating ATF4-Mediated Induction of FGF21 and ACOD1 Expression.

The non-coding RNA LINC00894 modulates tumor proliferation and drug resistance. However, its role in brain is still unclear. Using RNA-pull down combined with mass spectrometry and RNA binding protein immunoprecipitation, EIF5 was identified to interact with LINC00894. Furthermore, LINC00894 knockdown decreased EIF5 protein expression, whereas LINC00894 overexpression increased EIF5 protein expression in SH-SY5Y and BE(2)-M17 (M17) neuroblastoma cells. Additionally, LINC00894 affected the ubiquitination modification of EIF5. Adeno-associated virus (AAV) mediated LINC00894 overexpression in the brain inhibited the expression of activated Caspase-3, while increased EIF5 protein level in rats and mice subjected to transient middle cerebral artery occlusion reperfusion (MCAO/R). Meanwhile, LINC00894 knockdown increased the number of apoptotic cells and expression of activated Caspase-3, and its overexpression decreased them in the oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro models. Further, LINC00894 was revealed to regulated ATF4 protein expression in condition of OGD/R and normoxia. LINC00894 knockdown also decreased the expression of glutamate-cysteine ligase catalytic subunit (GCLC) and ATF4, downregulated glutathione (GSH), and the ratio of GSH to oxidized GSH (GSH: GSSG) in vitro. By using RNA-seq combined with qRT-PCR and immunoblot, we identified that fibroblast growth factor 21 (FGF21) and aconitate decarboxylase 1 (ACOD1), as the ATF4 target genes were regulated by LINC00894 in the MCAO/R model. Finally, we revealed that ATF4 transcriptionally regulated FGF21 and ACOD1 expression; ectopic overexpression of FGF21 or ACOD1 in LINC00894 knockdown cells decreased activated Caspase-3 expression in the OGD/R model. Our results demonstrated that LINC00894 regulated cerebral ischemia injury by stabilizing EIF5 and facilitating EIF5-ATF4-dependent induction of FGF21 and ACOD1.

Glycyrrhetinic acid triggers a protective autophagy by inhibiting the JAK2/STAT3 pathway in cerebral ischemia/reperfusion injury.

Cerebral ischemia/reperfusion injury (CIRI) is a common feature of ischemic stroke leading to a poor prognosis. Effective treatments targeting I/R injury are still insufficient. The study aimed to investigate the mechanisms, by which glycyrrhizic acid (18ß-GA) in ameliorates CIRI. Our results showed that 18ß-GA significantly decreased the infarct volume, neurological deficit scores, and pathological changes in the brain tissue of rats after middle cerebral artery occlusion. Western blotting showed that 18ß-GA inhibited the expression levels of phosphorylated JAK2 and phosphorylated STAT3. Meanwhile, 18ß-GA increased LC3-II protein levels in a reperfusion duration-dependent manner, which was accompanied by an increase in the Bcl-2/Bax ratio. Inhibition of 18ß-GA-induced autophagy by 3-methyladenine (3-MA) enhanced apoptotic cell death. In addition, 18ß-GA inhibited the JAK2/STAT3 pathway, which was largely activated in response to oxygen-glucose deprivation/reoxygenation. However, the JAK2/STAT3 activator colivelin TFA abolished the inhibitory effect of 18ß-GA, suppressed autophagy, and significantly decreased the Bcl-2/Bax ratio. Taken together, these findings suggested that 18ß-GA pretreatment ameliorated CIRI partly by triggering a protective autophagy via the JAK2/STAT3 pathway. Therefore might be a potential drug candidate for treating ischemic stroke.

Application progress of exergames in health interventions for the elderly. / 运动游戏在老年人健康干预中的应用进展.

With the aging population in China, health issues among the elderly are becoming increasingly prominent, leading to a rapidly growing demand for health interventions for the elderly. Exergames are one of the important emerging methods in the field of health interventions for the elderly, widely used and yielding positive results. While research on exergames is well-established abroad, it is still in its infancy in China, lacking reports on the types, interaction forms, intervention content, application status, and effectiveness of exergames. Exergames are suitable for widespread use among the elderly in China, and there is a need to accelerate the development and application of exergames in the field of health interventions for the elderly in China.

Examining the impact of flipped learning on second language development: A quasi-experiment in higher education.

This article reports on a study that examined the impact of a flipped English as a Foreign Language (EFL) course on college students' second language (L2) development. Specifically, an 18-week quasi-experiment was administered in a general English course at a Chinese university, with a total of 612 first-year students randomly assigned to the treatment (n = 137) and control (n = 475) groups. Using the propensity score matching and difference-in-differences (PSM-DID) model, we analyzed norm scores on high-stakes assessments administered on the entry and completion of the intervention. The results revealed a causal link between flipped learning (FL) and improved L2 language performance though the impact of FL had substantial heterogeneity as greater gains were found in reading than in writing and listening. Quantile regression analysis suggested the effectiveness of FL varied greatly by proficiency level in that students in the lowest quantiles achieved high improvement in reading and listening but moderate improvement in writing. We discuss the pedagogical implications of these findings to college L2 flipped instruction and recommend that future research be conducted in a more rigorous experimental design to obtain robust and accurate estimates of the effectiveness of FL.

Nasal Drug Delivery and Nose-to-Brain Delivery Technology Development Status and Trend Analysis: Based on Questionnaire Survey and Patent Analysis.

Nasal administration is a non-invasive method of drug delivery that offers several advantages, including rapid onset of action, ease of use, no first-pass effect, and fewer side effects. On this basis, nose-to-brain delivery technology offers a new method for drug delivery to the brain and central nervous system, which has attracted widespread attention. In this paper, the development status and trends of nasal drug delivery and nose-to-brain delivery technology are deeply analyzed through multiple dimensions: literature research, questionnaire surveys, and patent analysis. First, FDA-approved nasal formulations for nose-to-brain delivery were combed. Second, we collected a large amount of relevant information about nasal drug delivery through a questionnaire survey of 165 pharmaceutical industry practitioners in 28 provinces and 161 different organizations in China. Third, and most importantly, we conducted a patent analysis of approximately 700+ patents related to nose-to-brain delivery, both domestically and internationally. This analysis was conducted in terms of patent application trends, technology life cycle, technology composition, and technology evolution. The LDA topic model was employed to identify technological topics in each time window (1990-2023), and the five key major evolution paths were extracted. The research results in this paper will provide useful references for relevant researchers and enterprises in the pharmaceutical industry, promoting the further development and application of nasal drug delivery and nose-to-brain delivery technology.

Microplastics in soil affect the growth and physiological characteristics of Chinese fir and Phoebe bournei seedlings.

Pot experiments were conducted using Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) and Phoebe bournei (Hemsl.) Yang) to investigate whether soil microplastics adversely affect the nurturing and renewal of plantations. Microplastics composed of polyethylene and polypropylene with a size of 48 µm were used. The treatments included a control group (without microplastics) and groups treated with microplastic concentrations of 1% and 2% (w/w). The effects of microplastics on the growth, photosynthetic pigments in leaves, antioxidant systems, and osmotic regulation substances of the seedlings were analysed by measuring the seedling height, ground-line diameter growth, chlorophyll (chlorophyll a, chlorophyll b, and total chlorophyll) contents, antioxidant enzyme (superoxide dismutase, peroxidase, catalase) activities, and malondialdehyde, soluble sugar, and soluble protein levels. The results indicated that treatment with 1% polyethylene microplastics increased the chlorophyll a, total chlorophyll, and soluble protein contents in the leaves of both types of seedlings while inhibiting superoxide dismutase and peroxidase activities in P. bournei seedlings. Treatment with 2% polyethylene or polypropylene microplastics suppressed the chlorophyll a, chlorophyll b, and total chlorophyll contents; superoxide dismutase, peroxidase, and catalase activities; and soluble sugar and soluble protein levels in the leaves of both types of seedlings, resulting in reduced growth in terms of height and ground-line diameter. The physiological effects of polyethylene microplastics were more evident than those of polypropylene at the same concentration. The results demonstrated that microplastics can affect photosynthesis, the antioxidant system, and osmotic regulation in Chinese fir and P. bournei seedlings, thereby inhibiting their normal growth and development. Exposure to 1% (w/w) microplastics triggered stress responses in seedlings, whereas 2% (w/w) microplastics impeded seedling growth.

MiR-4465-modified mesenchymal stem cell-derived small extracellular vesicles inhibit liver fibrosis development via targeting LOXL2 expression. / MiR-4465修饰的间质干细胞来源的小细胞外囊泡通过靶向LOXL2表达抑制肝纤维化的进展.

Liver fibrosis is a significant health burden, marked by the consistent deposition of collagen. Unfortunately, the currently available treatment approaches for this condition are far from optimal. Lysyl oxidase-like protein 2 (LOXL2) secreted by hepatic stellate cells (HSCs) is a crucial player in the cross-linking of matrix collagen and is a significant target for treating liver fibrosis. Mesenchymal stem cell-derived small extracellular vesicles (MSC-sEVs) have been proposed as a potential treatment option for chronic liver disorders. Previous studies have found that MSC-sEV can be used for microRNA delivery into target cells or tissues. It is currently unclear whether microRNA-4465 (miR-4465) can target LOXL2 and inhibit HSC activation. Additionally, it is uncertain whether MSC-sEV can be utilized as a gene therapy vector to carry miR-4465 and effectively inhibit the progression of liver fibrosis. This study explored the effect of miR-4465-modified MSC-sEV (MSC-sEVmiR-4465) on LOXL2 expression and liver fibrosis development. The results showed that miR-4465 can bind specifically to the promoter of the LOXL2 gene in HSC. Moreover, MSC-sEVmiR-4465 inhibited HSC activation and collagen expression by downregulating LOXL2 expression in vitro. MSC-sEVmiR-4465 injection could reduce HSC activation and collagen deposition in the CCl4-induced mouse model. MSC-sEVmiR-4465 mediating via LOXL2 also hindered the migration and invasion of HepG2 cells. In conclusion, we found that MSC-sEV can deliver miR-4465 into HSC to alleviate liver fibrosis via altering LOXL2, which might provide a promising therapeutic strategy for liver diseases.

Bioinspired High-Linearity, Wide-Sensing-Range Flexible Stretchable Bioelectronics Based on MWCNTs/GR/Nd2Fe14B/PDMS Nanocomposites for Human-Computer Interaction and Biomechanics Detection.

In recent years, flexible and stretchable strain sensors have emerged as a prominent area of research, primarily due to their remarkable stretchability and extremely low strain detection threshold. Nevertheless, the advancement of sensors is currently constrained by issues such as complexity, high costs, and limited durability. To tackle the aforementioned issues, this study introduces a lepidophyte-inspired flexible, stretchable strain sensor (LIFSSS). The stretchable bioelectronics composites were composed of multiwalled carbon nanotubes, graphene, neodymium iron boron, and polydimethylsiloxane. Unique biolepidophyted microstructures and magnetic conductive nanocomposites interact with each other through synergistic interactions, resulting in the effective detection of tensile strain and magnetic excitation. The LIFSSS exhibits a 170% tensile range, a linearity of 0.99 in 50-170% strain (0.96 for full-scale range), and a fine durability of 7000 cycles at 110% tensile range. The sensor accurately detects variations in linear tensile force, human movement, and microexpressions. Moreover, LIFSSS demonstrates enhanced efficacy in sign language recognition for individuals with hearing impairments and magnetic grasping for robotic manipulators. Hence, the LIFSSS proposed in this study shows potential applications in various fields, including bioelectronics, electronic skin, and physiological activity monitoring.

Synergistically improve the strength and porosity of carbon paper by using a novel phenol formaldehyde resin modified with cellulose nanofiber for proton exchange membrane fuel cells.

To optimize the imbalance between the interfacial bonding and porosity properties of carbon paper (CP) caused by phenol formaldehyde resin (PF) impregnation, and therefore improve the performance of proton exchange membrane fuel cells (PEMFCs), a new approach through cellulose nanofibers grafted with methyl methacrylate (CNFM) as a modified reinforcement and pore-forming agent for PF is investigated. Through suppressing the methylene backbone fracture of CNFM-modified PF during its thermal depolymerization, the interfacial bonding between PF matrix carbon and carbon fibers is enhanced. Compared with unmodified CP, the in-plane resistivity of CNFM-modified CP is reduced by 35.78 %, while the connected porosity increases to 82.26 %, and more homogeneous pore size distribution (PSD) in the range of 20-40 µm is obtained for CNFM-modified CP. Besides, the tensile strength, flexural strength, and air permeability of CNFM-modified CP increase by 72.78 %, 298.4 %, and 103.97 %, respectively. In addition, CNFM-modified CP achieves the peak power density of PEMFCs to 701.81 mW·cm-2, exhibiting 10.98 % improvement compared with commercial CP (632.39 mW·cm-2), evidently achieving an integral promotion of CP and comprehensive performance.

Motor adaptation is reduced by symbolic compared to sensory feedback.

Motor adaptation - the process of reducing motor errors through feedback and practice - is an essential feature of human competence, allowing us to move accurately in dynamic and novel environments. Adaptation typically results from sensory feedback, with most learning driven by visual and proprioceptive feedback that arises with the movement. In humans, motor adaptation can also be driven by symbolic feedback. In the present study, we examine how implicit and explicit components of motor adaptation are modulated by symbolic feedback. We conducted three reaching experiments involving over 400 human participants to compare sensory and symbolic feedback using a task in which both types of learning processes could be operative (Experiment 1) or tasks in which learning was expected to be limited to only an explicit process (Experiments 2 and 3). Adaptation with symbolic feedback was dominated by explicit strategy use, with minimal evidence of implicit recalibration. Even when matched in terms of information content, adaptation to rotational and mirror reversal perturbations was slower in response to symbolic feedback compared to sensory feedback. Our results suggest that the abstract and indirect nature of symbolic feedback disrupts strategic reasoning and/or refinement, deepening our understanding of how feedback type influences the mechanisms of sensorimotor learning.

Single-pixel Fresnel incoherent correlation holography compressed imaging using a Trumpet network.

Fresnel incoherent correlation holography (FINCH) can achieve high-precision and non-scanning 3D imaging. However, as a holographic imaging technology, the huge bandwidth requirements and the amount of holographic data transmitted have always been one of the important factors limiting its application. In addition, the hardware cost of pixel array-based CCD or CMOS imaging is very high under high resolution or specific wavelength conditions. Accordingly, a single-pixel Fresnel incoherent correlation holography (SP-FINCH) compressed imaging method is proposed, which replaces pixel array detector with single-pixel detector and designs a Trumpet network to achieve low-cost and high-resolution imaging. Firstly, a modified FINCH imaging system is constructed and data acquisition is carried out using a single-pixel detector. Secondly, a Trumpet network is constructed to directly map the relationship between one-dimensional sampled data and two-dimensional image in an end-to-end manner. Moreover, by comparing the reconstructed images using neural network with that using commonly used single-pixel reconstruction methods, the results indicate that the proposed SP-FINCH compressed imaging method can significantly improve the quality of image reconstruction at lower sampling rate and achieve imaging without phase-shifting operation. The proposed method has been shown to be feasible and advantageous through numerical simulations and optical experiment results.

Knockdown of ATRX enhances radiosensitivity in glioblastoma.

BACKGROUND: Glioblastoma are highly malignant type of primary brain tumors. Treatment for glioblastoma multiforme (GBM) generally involves surgery combined with chemotherapy and radiotherapy. However, the development of tumoral chemo- and radioresistance induces complexities in clinical practice. Multiple signaling pathways are known to be involved in radiation-induced cell survival. However, the role of alpha-thalassemia X-linked mutant retardation syndrome (ATRX), a chromatin remodeling protein, in GBM radioresistance remains unclear. METHODS: In the present study, the ATRX mutation rate in patients with glioma was obtained from The Cancer Genome Atlas, while its expression analyzed using bioinformatics. Datasets were also obtained from the Gene Expression Omnibus, and ATRX expression levels following irradiation of GBM were determined. The effects of ATRX on radiosensitivity were investigated using a knockdown assays. RESULTS: The present study demonstrated that the ATRX mutation rate in patients with GBM was significantly lower than that in patients with low-grade glioma, and that patients harboring an ATRX mutation exhibited a prolonged survival, compared with to those harboring the wild-type gene. Single-cell RNA sequencing demonstrated that ATRX counts increased 2 days after irradiation, with ATRX expression levels also increasing in U-251MG radioresistant cells. Moreover, the results of in vitro irradiation assays revealed that ATRX expression was increased in U-251MG cells, while ATRX knockdown was associated with increased levels of radiosensitivity. CONCLUSIONS: High ATRX expression levels in primary GBM may contribute to high levels of radioresistance. Thus ATRX is a potential target for overcoming the radioresistance in GBM.

Glutamine Protects against Mouse Abdominal Aortic Aneurysm through Modulating VSMC Apoptosis and M1 Macrophage Activation.

Glutamine (Gln), known as the most abundant free amino acid, is widely spread in human body. In this study, we demonstrated the protective effects of glutamine against mouse abdominal aortic aneurysm (AAA) induced by both angiotensin II (AngII) and calcium phosphate (Ca3(PO4)2) in vivo, which was characterized with lower incidence of mouse AAA. Moreover, histomorphological staining visually presented more intact elastic fiber and less collagen deposition in abdominal aortas of mice treated by glutamine. Further, we found glutamine inhibited the excessive production of reactive oxide species (ROS), activity of matrix metalloproteinase (MMP), M1 macrophage activation, and apoptosis of vascular smooth muscle cells (VSMCs) in suprarenal abdominal aortas of mice, what's more, the high expressions of MMP-2 protein, MMP-9 protein, pro-apoptotic proteins, and IL-6 as well as TNF-α in protein and mRNA levels in cells treated by AngII were down-regulated by glutamine. Collectively, these results revealed that glutamine protected against mouse AAA through inhibiting apoptosis of VSMCs, M1 macrophage activation, oxidative stress, and extracellular matrix degradation.

Endobronchial ultrasound-guided transbronchial needle aspiration for diagnosing thoracic lesions: a retrospective cohort study.

Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a minimally invasive technique for biopsy of lung, peri-pulmonary tissue and lymph nodes under real-time ultrasound-guided biopsy. It is used in the diagnosis and/or staging of benign and malignant pulmonary and non-pulmonary diseases. Our study is based on a large sample size, in a diversified population which provides a representative real-world cohort for analysis. Methods: Patients who underwent EBUS-TBNA procedure between September 2019 and August 2022 were included in this retrospective study. For cases diagnosed as benign and unclassified lesions by EBUS-TBNA, the final diagnosis was determined by further invasive surgery or a combination of therapy and clinical follow-up for at least 6 months. Results: A total of 618 patients were included in the study, including 182 females (29.4%) and 436 males (70.6%). The mean age of all patients was 61.9 ± 10.5 years. These patients were successfully punctured by EBUS-TBNA to obtain pathological results. The pathological diagnosis results of EBUS-TBNA were compared with the final clinical diagnosis results as follows: 133 cases (21.5%) of benign lesions and 485 cases (78.5%) of malignant lesions were finally diagnosed. Among them, the pathological diagnosis was obtained by EBUS-TBNA in 546 patients (88.3%) (464 malignant lesions and 82 benign conditions), while EBUS-TBNA was unable to define diagnosis in 72 patients (11.6%). 20/72 non-diagnostic EBUS-TBNA were true negative. The overall diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of EBUS-TBNA were 91.3%, 100%, 100%, 27.8%, and 91.6% [95% confidence interval (CI): 89.1-93.6%], respectively. In this study, only one case had active bleeding without serious complications during the EBUS-TBNA procedure. Conclusion: Given its low invasiveness, high diagnostic accuracy, and safety, EBUS-TBNA is worth promoting in thoracic lesions.

Increased TMEM166 Level in Patients with Postoperative Stroke after Carotid Endarterectomy.

Postoperative stroke is a challenging and potentially devastating complication after elective carotid endarterectomy (CEA). We previously demonstrated that transmembrane protein 166 (TMEM166) levels were directly related to neuronal damage after cerebral ischemia-reperfusion injury in rats. In this subsequent clinical study, we aimed to evaluate the prognostic value of TMEM166 in patients suffering from post-CEA strokes. Thirty-five patients undergoing uncomplicated elective CEA and 8 patients who suffered ischemic strokes after CEA were recruited. We evaluated the protein level and expression of TMEM166 in patients diagnosed with postoperative strokes and compared it to those in patients who underwent uncomplicated elective CEA. Blood samples and carotid artery plaques were collected and analyzed. High expressions of TMEM166 were detected by immunofluorescence staining and Western Blot in carotid artery plaques of all patients who underwent CEA. Furthermore, circulating TMEM166 concentrations were statistically higher in post-CEA stroke patients than in patients allocated to the control group. Mean plasma concentrations of inflammatory markers, including interleukin 6 (IL-6) and C-reactive protein (CRP), were also elevated in patients with postoperative strokes. Therefore, based on these findings, we hypothesize that elevated TMEM166 levels, accompanied by a strong inflammatory response, serve as a useful biomarker for risk assessment of postoperative stroke following CEA.

Effectiveness of gonadotropin-releasing hormone agonists for ovarian function suppression in premenopausal patients with hormone receptor-positive breast cancer: a retrospective single-center real-world study.

PURPOSE: This study evaluated the effectiveness of ovarian function suppression (OFS) of various gonadotropin-releasing hormone agonists (GnRHa) combined with aromatase inhibitors (AI) in premenopausal patients with hormone receptor-positive (HR-positive) breast cancer. Potential risk factors associated with insufficient OFS were analyzed. PATIENTS AND METHODS: Premenopausal HR-positive breast cancer patients who had received AI with GnRHa were studied retrospectively. Patients were divided into different groups according to monthly or trimonthly GnRHa schedules they received, and the effectiveness of OFS was compared between groups. Insufficient OFS was defined as at least one instance of estradiol ≥ 30 pg/ml. Patient data was gathered from medical records for this comparison. RESULTS: Of the 264 patients enrolled in this study, 117 were administered 3.6 mg of goserelin monthly (goserelin 1 M group), 63 received 3.75 mg of leuprorelin monthly (leuprorelin 1 M group) and 84 were given 11.25 mg of leuprorelin every three months (leuprorelin 3 M group). Overall, 7.20% experienced insufficient OFS. The incidence rates in the three GnRHa depot groups were 7.69%, 6.35%, and 7.14%, respectively, without a significant statistical difference (P = 0.900). Notably, younger patients exhibited a higher likelihood of insufficient OFS [OR = 0.900, 95%CI (0.824-0.982), P = 0.018]. CONCLUSION: Insufficient OFS remains a concern during GnRHa and AI treatment. The effectiveness of the three GnRHa depots commonly used in China seems comparable. Younger patients face a heightened risk of insufficient OFS.

De novo transcriptome assembly database for 100 tissues from each of seven species of domestic herbivore.

Domesticated herbivores are an important agricultural resource that play a critical role in global food security, particularly as they can adapt to varied environments, including marginal lands. An understanding of the molecular basis of their biology would contribute to better management and sustainable production. Thus, we conducted transcriptome sequencing of 100 to 105 tissues from two females of each of seven species of herbivore (cattle, sheep, goats, sika deer, horses, donkeys, and rabbits) including two breeds of sheep. The quality of raw and trimmed reads was assessed in terms of base quality, GC content, duplication sequence rate, overrepresented k-mers, and quality score distribution with FastQC. The high-quality filtered RNA-seq raw reads were deposited in a public database which provides approximately 54 billion high-quality paired-end sequencing reads in total, with an average mapping rate of ~93.92%. Transcriptome databases represent valuable resources that can be used to study patterns of gene expression, and pathways that are related to key biological processes, including important economic traits in herbivores.

Ultrahigh extinction ratio and a low power silicon thermo-optic switch.

The silicon thermo-optic switch (TOS) is one of the most fundamental and crucial blocks in large-scale silicon photonic integrated circuits (PICs). An energy-efficient silicon TOS with ultrahigh extinction ratio can effectively mitigate cross talk and reduce power consumption in optical systems. In this Letter, we demonstrate a silicon TOS based on cascading Mach-Zehnder interferometers (MZIs) with spiral thermo-optic phase shifters. The experimental results show that an ultrahigh extinction ratio of 58.8 dB is obtained, and the switching power consumption is as low as 2.32 mW/π without silicon air trench. The rise time and fall time of the silicon TOS are about 10.8 and 11.2 µs, respectively. Particularly, the figure of merit (FOM) has been improved compared with previously reported silicon TOS. The proposed silicon TOS may find potential applications in optical switch arrays, on-chip optical delay lines, etc.