Association of pyrethroids exposure with asthma in US children and adolescents: a nationally representative cross-sectional study.

Pyrethroids (PYR) are among the most widely used insecticides in households, leading to substantial exposure. Children and adolescents, especially during growth spurts, have a reduced capacity to effectively metabolize these insecticides. The relationship between PYR exposure and asthma in these age groups remains poorly understood, highlighting the need for further research.We used data from the 2007-2014 National Health and Nutrition Examination Survey, which included 1181 children aged 6-11 years and 1258 adolescents aged 12-19 years. The concentration of the PYR metabolite 3-phenoxybenzoic acid (3-PBA) in urine was quantified using solid-phase extraction-high-performance liquid chromatography-heated electrospray ionization tandem mass spectrometry. Asthma was defined based on self-reported doctor diagnoses from the questionnaire. PYR exposure was measured using urine samples collected simultaneously with the questionnaire. We explored the association between PYR exposure and asthma using multiple logistic regression analyses, adjusting for potential confounders.Multiple logistic regression analyses revealed no significant association between PYR exposure and asthma in children and adolescent boys (all P > 0.05). In contrast, PYR exposure was significantly associated with asthma in adolescent girls aged 12-19 years. Specifically, for "ever asthma," the odds ratios (ORs) were 2.49 (95% CI = 1.03-5.97) in the second quartile of PYR exposure and 2.48 (95% CI = 1.04-5.91) in the third quartile, each in comparison to the first quartile. For "current asthma," in comparison to the first quartile, the ORs were 3.99 (95% CI = 1.55-10.26) in the second quartile of PYR exposure, 3.39 (95% CI = 1.32-8.70) in the third quartile, and 2.93 (95% CI = 1.24-6.90) in the fourth quartile.Conclusions:Our study found a significant association between PYR exposure and asthma in adolescent girls, whereas no significant association was observed in children and adolescent boys. These findings suggest potential sex and age differences in susceptibility to PYR exposure. Further research is warranted to confirm these results and elucidate the underlying mechanisms.

Environmental exposure to per- and polyfluoroalkyl substances mixture and asthma in adolescents.

BACKGROUND: Previous epidemiological studies about the relationship between per- and polyfluoroalkyl substances (PFAS) concentrations and adolescent asthma have typically examined single PFAS, without considering the mixtures effects of PFAS. METHODS: Using data from the 2013-2018 National Health and Nutrition Examination Survey (NHANES), 886 adolescents aged 12-19 years were included in this study. We explored the association between PFAS mixture concentrations and adolescent asthma using weighted quantile sum (WQS) regression and Bayesian kernel machine regression (BKMR) models, respectively. RESULTS: After adjusting for confounders, the results of the WQS regression and BKMR models were consistent, with mixed exposure to the five PFAS not significantly associated with asthma in all adolescents. The association remained nonsignificant in the subgroup analysis by sex. CONCLUSIONS: Our study demonstrated no significant association between mixed exposure to PFAS and adolescent asthma, and more large cohort studies are needed to confirm this in the future.

Salt-Inducible Kinase 3 Promotes Vascular Smooth Muscle Cell Proliferation and Arterial Restenosis by Regulating AKT and PKA-CREB Signaling.

Objective: Arterial restenosis is the pathological narrowing of arteries after endovascular procedures, and it is an adverse event that causes patients to experience recurrent occlusive symptoms. Following angioplasty, vascular smooth muscle cells (SMCs) change their phenotype, migrate, and proliferate, resulting in neointima formation, a hallmark of arterial restenosis. SIKs (salt-inducible kinases) are a subfamily of the AMP-activated protein kinase family that play a critical role in metabolic diseases including hepatic lipogenesis and glucose metabolism. Their role in vascular pathological remodeling, however, has not been explored. In this study, we aimed to understand the role and regulation of SIK3 in vascular SMC migration, proliferation, and neointima formation. Approach and Results: We observed that SIK3 expression was low in contractile aortic SMCs but high in proliferating SMCs. It was also highly induced by growth medium in vitro and in neointimal lesions in vivo. Inactivation of SIKs significantly attenuated vascular SMC proliferation and up-regulated p21CIP1 and p27KIP1. SIK inhibition also suppressed SMC migration and modulated actin polymerization. Importantly, we found that inhibition of SIKs reduced neointima formation and vascular inflammation in a femoral artery wire injury model. In mechanistic studies, we demonstrated that inactivation of SIKs mainly suppressed SMC proliferation by down-regulating AKT (protein kinase B) and PKA (protein kinase A)-CREB (cAMP response element-binding protein) signaling. CRTC3 (CREB-regulated transcriptional coactivator 3) signaling likely contributed to SIK inactivation-mediated antiproliferative effects. Conclusions: These findings suggest that SIK3 may play a critical role in regulating SMC proliferation, migration, and arterial restenosis. This study provides insights into SIK inhibition as a potential therapeutic strategy for treating restenosis in patients with peripheral arterial disease.

Impact of the COVID-19 pandemic on career intention amongst undergraduate medical students: a single-centre cross-sectional study conducted in Hubei Province.

BACKGROUND: Undergraduate medical (UM) students faced the difficulties inherent in medical careers due to the coronavirus (COVID-19) outbreak. Thus, imperative containment measures might affect UM students' career intentions. Information on the factors that may be associated with these students' career change intentions is limited. METHODS: We conducted a cross-sectional survey in August 2020 to investigate the impact of the COVID-19 pandemic on career intention and the associated factors in UM students. Univariate analyses and logistic regression analysis were performed to identify said factors. RESULTS: A total of 2040 medical students from the Hubei University of Medicine were surveyed. Univariate analyses showed that grade, attitude towards healthcare, and the degree of the COVID-19 pandemic's impact on the students' lives were associated with changes in career choice (P<0.05). Logistic regression analysis showed that Grade 2, Grade 5, attitude towards a medical career, and having relatives with a medical background were associated with changes in career choice. The degree of the COVID-19 pandemic's impact was a common and significant factor associated with career preference, career perspective, and ideal workplace. CONCLUSIONS: Changes in career intentions were particularly influenced by grade, attitude towards being a health worker, and the degree of COVID-19's impact on the participants' lives. Treating large-scale public health emergencies rationally, setting up correct views of occupation choice, and building reasonable career planning may reduce the loss of medical talent.

[4-nonylphenol combined with bisphenol A induces testicular autophagy and spermatogenic impairment by inhibiting the Akt/mTOR pathway in F1 male offspring rats].

OBJECTIVE: To study the impacts of exposure of F0 generation rats to 4-nonylphenol (4-NP) and bisphenal A (BPA) on the autophagy of testicular cells and key gene expressions of the Akt/mTOR pathway in the F1 generation offspring rats. METHODS: Using a 2×2 factorial design, F0 female and male rats were randomly assigned to receive intragastrically sigma vegetable oil (the control), BPA at 0.5 mg/kg, 4-NP at 5 mg/kg, and BPA+4-NP both at 0.5 mg/kg, respectively, qd alt for 30 days. Then the rats in each group were mated at a ratio of 1∶3. After pregnancy, the female rats continued the above intragastrical administration till delivery. The F1 generation male offspring rats were killed at 60 postnatal days, and their testes harvested for sperm count, observation of the morphological and autophagic changes of the testis, and determination of the relative mRNA expression levels of Akt, mTOR, 4EBP1 and p70S6K and protein expression levels of LC3-I and LC3-II. RESULTS: The sperm count of the F1 generation male offspring rats was markedly decreased in the BPA and BPA+4-NP groups compared with that in the control (P < 0.05) but no significant interactive effect was observed between BPA and 4-NP (P > 0.05). The ratio of LC3-II / LC3-I was remarkably increased in the 4-NP, BPA and BPA+4-NP groups in comparison with that in the control (P < 0.05), and a significant interactive effect was shown between BPA and 4-NP (P < 0.05). The cells in the seminiferous tubules of the rats in the 4-NP, BPA and BPA+4-NP groups were loosely arranged, with a decreased count of sperm and increased number of autophagic vacuoles. Significant down-regulation was observed in the relative mRNA expression of p70S6K in the 4-NP group, as well as in that of mTOR in the BPA group and Akt in the BPA+4-NP group (all P < 0.05). A remarkably up-regulated expression of 4EBP1 mRNA was found in all the three intervention groups (P < 0.05), with a significant interactive effect between BPA and 4-NP on the expressions of Akt and 4EBP1 mRNA (P < 0.05). CONCLUSION: Long-term exposure to low-concentration BPA and 4-NP impairs the testicular function of the F1 generation male offspring rats, which is closely related to the autophagy of testicular cells and changes of the Akt/mTOR pathway.

A new molecular nomenclature for Taenia hydatigena: mitochondrial DNA sequences reveal sufficient diversity suggesting the assignment of major haplotype divisions.

Cysticercosis caused by the metacestode larval stage of Taenia hydatigena formerly referred to as Cysticercus tenuicollis is a disease of veterinary importance that constitutes a significant threat to livestock production worldwide, especially in endemic regions due to condemnation of visceral organs and mortality rate of infected young animals. While the genetic diversity among parasites is found to be potentially useful in many areas of research including molecular diagnostics, epidemiology and control, that of T. hydatigena across the globe remains poorly understood. In this study, analysis of the mitochondrial DNA (mtDNA) of adult worms and larval stages of T. hydatigena isolated from dogs, sheep and a wild boar in China showed that the population structure consists of two major haplogroups with very high nucleotide substitutions involving synonymous and non-synonymous changes. Compared with other cestodes such as Echinococcus spp., the genetic variation observed between the haplogroups is sufficient for the assignment of major haplotype or genotype division as both groups showed a total of 166 point-mutation differences between the 12 mitochondrial protein-coding gene sequences. Preliminary analysis of a nuclear protein-coding gene (pepck) did not reveal any peculiar changes between both groups which suggests that these variants may only differ in their mitochondrial makeup.

Pooled analysis of Xpert Bladder Cancer based on the 5 mRNAs for rapid diagnosis of bladder carcinoma.

BACKGROUND: Xpert Bladder Cancer is a detection method developed in recent years, designed with the functions of integrating sample automatically, nucleic acid amplification, and target sequence detection. It is a urine assay targeting five mRNAs (CRH, IGF2, UPK1B, ANXA10, and ABL1). The purpose of this article is to review the accuracy of Xpert Bladder Cancer in the follow-up diagnosis of bladder cancer and evaluate the role of Xpert Bladder Cancer in detecting the recurrence of non-muscle-invasive bladder cancer in the round. METHODS: In the database of Embase, PubMed, Web of Science, and Cochrane Library, the articles published up to October 13, 2020, were searched and screened based on the exclusion and inclusion criteria, and data were extracted from the included studies. The sensitivity, specificity, negative likelihood ratio, positive likelihood ratio summary of receiver operating characteristic curves, and diagnostic odds ratio were combined by the Meta-DiSc 1.4 software. The Stata 12.0 software was used to obtain the assessment of publication bias. RESULTS: A total of 8 articles involving eight fourfold tables were finally identified. The pooled sensitivity and specificity of Xpert Bladder Cancer in the diagnosis of bladder cancer were 0.71 and 0.81, respectively. The positive likelihood ratio and negative likelihood ratio were 3.74 and 0.34, respectively. The area under the curve was 0.8407. The diagnostic odds ratio was 11.99. Deeks' funnel plot asymmetry test manifested no publication bias. CONCLUSIONS: In summary, Xpert Bladder Cancer presents high accuracy and specificity in monitoring bladder cancer compared with cystoscopy. More researches are still required to further confirm this conclusion.

Application of the respiratory "critical care-sub-critical care-rehabilitation integrated management model" in severe stroke associated pneumonia.

BACKGROUND: This study aimed to explore the feasibility of applying the respiratory "critical care-sub-critical care-rehabilitation integrated management model" in severe stroke-associated pneumonia and evaluate its effect. METHODS: From January to September 2018, 24 patients with severe stroke-associated pneumonia, who were admitted to the Respiratory Intensive Care Unit of the Respiratory and Critical Care Medicine Department of Henan Provincial People's Hospital, were randomly divided into two groups: integrated management group and control group. According to the admission criteria of the respiratory "critical care-sub-critical care-rehabilitation integrated model" prescribed by the above-mentioned hospital, patients were grouped. The professional respiratory therapy team participated in the whole treatment. The acute physiology and chronic health evaluation II (APACHE II) score, clinical pulmonary infection score (CPIS) and oxygenation index of these two groups were dynamically observed, and the average hospital stay, 28-day mortality and patient satisfaction were investigated. RESULTS: Patients in the integrated management group and control group were similar before treatment (P > 0.05). After treatment, the main indicators, the APACHE II score, CPIS score and oxygenation index, were significantly different between the integration group and control group (P < 0.05). The secondary indicators, the average hospitalization days and patient/family member satisfaction scores, were also significantly different between the integration group and control group (P < 0.05). However, the 28-day mortality wasn't significantly different (P > 0.05). CONCLUSIONS: For patients with severe stroke-associated pneumonia, it was feasible to implement the respiratory "critical care-sub-critical care-rehabilitation integrated management model", which could significantly improve the treatment effect, shorten average hospitalization days and improve patient/family satisfaction.

Investigation of Ion-Solvent Interactions in Nonaqueous Electrolytes Using in Situ Liquid SIMS.

Ion-solvent interactions in nonaqueous electrolytes are of fundamental interest and practical importance, yet debates regarding ion preferential solvation and coordination numbers persist. In this work, in situ liquid SIMS was used to examine ion-solvent interactions in three representative electrolytes, i.e., lithium hexafluorophosphate (LiPF6) at 1.0 M in ethylene carbonate (EC)-dimethyl carbonate (DMC) and lithium bis(fluorosulfonyl)imide (LiFSI) at both low (1.0 M) and high (4.0 M) concentrations in 1,2-dimethoxyethane (DME). In the positive ion mode, solid molecular evidence strongly supports the preferential solvation of Li+ by EC. Besides, from the negative spectra, we also found that PF6- forms association with EC, which has been neglected by previous studies due to the relatively weak interaction. In both LiFSI in DME electrolytes, however, no evidence shows that FSI- is associated with DME. Furthermore, strong salt ion cluster signals were observed in the 1.0 M LiPF6 in EC-DMC electrolyte, suggesting that a significant amount of Li+ ions stay in the vicinity of anions. In sharp comparison, weak ion cluster signals were detected in dilute LiFSI in DME electrolyte, suggesting most ions are well separated, in agreement with our molecular dynamics simulation results. These findings indicate that with virtues of little bias on detecting positive and negative ions and the capability of directly analyzing concentrated electrolytes, in situ liquid SIMS is a powerful tool that can provide key evidence for improved understanding on the ion-solvent interactions in nonaqueous electrolytes. Therefore, we anticipate wide applications of in situ liquid SIMS on investigations of various ion-solvent interactions in the near future.

Dorsomorphin homologue 1, a highly selective small-molecule bone morphogenetic protein inhibitor, suppresses medial artery calcification.

BACKGROUND: Medial artery calcification develops in diabetes, chronic kidney disease, and as part of the aging process. It is associated with increased morbidity and mortality in vascular patients. Bone morphogenetic proteins (BMPs) have previously been implicated in the initiation and progression of vascular calcification. We thus evaluated whether dorsomorphin homologue 1 (DMH1), a highly selective BMP inhibitor, could attenuate vascular calcification in vitro and in an organ culture model of medial calcification. METHODS: Confluent human aortic smooth muscle cells (SMCs) were cultured in calcification medium containing 3.0 mM inorganic phosphate (Pi) for 7 days with or without DMH1. Medial calcification was assessed using an aortic organ culture model. Calcification was visualized by alizarin red S staining, and calcium concentration was assessed by an o-cresolphthalein complexone calcium assay. Osteogenic cell and vascular SMC markers were determined by Western blot, quantitative reverse transcription polymerase chain reaction, and immunohistochemical staining. RESULTS: DMH1 reduced Pi-induced calcium deposition in human SMCs. It also antagonized human recombinant BMP2-induced calcium accumulation. Western blot further revealed that DMH1 was able to block Pi-mediated upregulation of the osteoblast markers osterix and alkaline phosphatase and downregulation of the SMC markers smooth muscle myosin heavy chain and SM22α as well as p-Smad1/5/8, suggesting that DMH1 may regulate SMC osteogenic differentiation through the BMP/Smad1/5/8 signaling pathway. Finally, using an ex vivo aortic ring organ culture model, we observed that DMH1 reduces Pi-induced aortic medial calcification. CONCLUSIONS: The selective BMP inhibitor DMH1 can inhibit calcium accumulation in vascular SMCs and arterial segments exposed to elevated phosphate levels. Such small molecules may have clinical utility in reducing medial artery calcification in our population of vascular patients.

An investigation of the beam damage effect on in situ liquid secondary ion mass spectrometry analysis.

RATIONALE: During in situ liquid secondary ion mass spectrometry (SIMS) analysis, the primary ion beam is normally scanned on a very small area to collect signals with high ion doses (1014 to 1016 ions/cm2 ). As a result, beam damage may become a concern when compared with the static limit of SIMS analysis, in which the dose is normally less than 1012 ions/cm2 . Therefore, a comparison of ion yields in in situ liquid SIMS analysis versus traditional static SIMS analysis of corresponding dry samples is of great interest. METHODS: In this study, a dipalmitoylphosphatidylcholine (DPPC) liposome solution was used as a model system. Both liquid sample and dry sample were examined. Secondary ion yields using three primary ion species (Bi+ , Bi3+ and Bi3++ ) with various beam currents were investigated. RESULTS: Usable ion yields for both positive and negative characteristic signals (including molecular ions and characteristic fragment ions) were achievable based on optimized experimental conditions for in situ liquid SIMS analysis. The ion yield of the key DPPC molecular ion was comparable to that of traditional static SIMS, and unexpected low fragmentation was observed. The flexible structure of the liquid plays an important role for these observations. CONCLUSIONS: Therefore, beam damage may not be a concern in in situ liquid SIMS analysis if proper experimental conditions are used.

Investigation of a chalcohalide glass optical waveguide structure fabricated by dual-energy carbon-ion implantation.

A planar waveguide structure in a chalcohalide glass was fabricated by dual-energy C ion implantation with energies of 5.5 and 6.0 MeV at fluences of 7.0×10¹4 and 8.0×10¹4ions cm⁻², respectively. A waveguide with a thickness of 5.9 µm was formed. SRIM 2013 was used to simulate the defect distribution fabricated by C ion implantation. Images of the polished end face of the C-implanted chalcohalide glass were measured with a metallographic microscope using reflected polarized light. The micro-Raman spectra were measured in air. The near-field intensity distributions were investigated at visible (633 nm) and near-infrared (1300, 1400, and 1539 nm) bands.

Visible and near-infrared optical properties of a proton-implanted KTP waveguide.

In this work, the optical properties of potassium titanyl phosphate (KTP) waveguides in the visible and near-infrared region are reported. The KTP waveguides were fabricated using 550 keV proton implantation at room temperature, and the refractive index profiles of the implanted region in the visible and near-infrared region were reconstructed. The profiles of the guided modes were measured through the end-face coupling method with both 632.8 and 1539 nm laser sources and then compared with the simulation results using the beam propagation method. Optical transmission and Raman spectra in the original substrate and waveguide active region were measured to study microstructural changes. The propagation loss of the TM0-mode at 632.8 nm was also measured.

Comparison of waveguide properties and Raman spectroscopic visualization of C and O ion implantation on LaAlO(3) crystals.

LaAlO3 crystals were implanted by C ions and O ions at an energy of 6.0 MeV with a fluence of 1.5×1015 ions/cm2. The profiles of the guided modes were measured through prism coupling and end-face coupling methods with a 633 nm laser source. A nonleaky waveguide structure in the TM mode was fabricated by O ion implantation after a proper annealing treatment. Characteristics of the implanted C and O ions were compared. Some changes of the full width at half of the maximum and intensity of the Raman spectra were observed between the waveguide and substrate regions in LaAlO3 crystals. Thus, the Raman spectra can be used to visualize any damage or defects in the LaAlO3 crystals during the implantation process.

[Accuracy and clinical efficacy of robot-assisted transiliac-transsacral screw placement for posterior pelvic ring fractures].

OBJECTIVE: To explore accuracy and clinical effect of robot-assisted implantation of sacroiliac penetrating screw in orthopedic surgery for posterior pelvic ring fracture. METHODS: The clinical data of 24 patients with posterior pelvic ring fracture treated with robot-assisted sacroiliac penetration screws from August 2022 to August 2023 were retrospectively analyzed, including 10 males and 14 females; aged from 21 to 73 years old with an average of (49.29±14.48) years old;according to Tile pelvic fractures, 13 patients were type B and 11 were type C. The effect of screw placement was evaluated according to Gras criteria based on postoperative CT scan results. At the final follow-up, fracture healing was evaluated according to Matta score, and functional recovery was evaluated by Majeed score. RESULTS: All patients were followed up for 3 to 13 months with an average of (6.00±3.28) months. Totally 36 sacroiliac penetrating screws, 18 S1 penetrating screws, 18 S2 penetrating screws were inserted, a total of 29 were excellent and 7 good according to Gras standard. Screw adjustment times was 0.00 (0.00, 0.75) times. At the final follow-up, Matta score was excellent in 18 patients, 5 good and 1 moderate, and the maximum displacement distance was 2.55 (0.00, 5.65) mm. Majeed score was 84.37±8.38, 15 patients were excellent, 7 good and 2 moderate. CONCLUSION: Robot could accurately and safely assist in the placement of sacroiliac joint screws for the treatment of posterior pelvic ring fractures, and promote postoperative functional recovery of patients.

Smooth muscle cell-specific matrix metalloproteinase 3 deletion reduces osteogenic transformation and medial artery calcification.

AIMS: Vascular calcification is highly prevalent in atherosclerosis, diabetes, and chronic kidney disease. It is associated with increased morbidity and mortality in patients with cardiovascular disease. Matrix metalloproteinase 3 (MMP-3), also known as stromelysin-1, is part of the large matrix metalloproteinase family. It can degrade extracellular matrix components of the arterial wall including elastin, which plays a central role in medial calcification. In this study, we sought to determine the role of MMP-3 in medial calcification. METHODS AND RESULTS: We found that MMP-3 was increased in rodent models of medial calcification as well as in vascular smooth muscle cells (SMCs) cultured in a phosphate calcification medium. It was also highly expressed in calcified tibial arteries in patients with peripheral arterial disease (PAD). Knockdown and inhibition of MMP-3 suppressed phosphate-induced SMC osteogenic transformation and calcification, whereas the addition of a recombinant MMP-3 protein facilitated SMC calcification. In an ex vivo organ culture model and a rodent model of medial calcification induced by vitamin D3, we found that MMP-3 deficiency significantly suppressed medial calcification in the aorta. We further found that medial calcification and osteogenic transformation were significantly reduced in SMC-specific MMP-3-deficient mice, suggesting that MMP-3 in SMCs is an important factor in this process. CONCLUSION: These findings suggest that MMP-3 expression in vascular SMCs is an important regulator of medial calcification and that targeting MMP-3 could provide a therapeutic strategy to reduce it and address its consequences in patients with PAD.

Altered spontaneous brain activity patterns in hypertensive retinopathy using fractional amplitude of low-frequency fluctuations: a functional magnetic resonance imaging study.

AIM: To study functional brain abnormalities in patients with hypertensive retinopathy (HR) and to discuss the pathophysiological mechanisms of HR by fractional amplitude of low-frequency fluctuations (fALFFs) method. METHODS: Twenty HR patients and 20 healthy controls (HCs) were respectively recruited. The age, gender, and educational background characteristics of the two groups were similar. After functional magnetic resonance imaging (fMRI) scanning, the subjects' spontaneous brain activity was evaluated with the fALFF method. Receiver operating characteristic (ROC) curve analysis was used to classify the data. Further, we used Pearson's correlation analysis to explore the relationship between fALFF values in specific brain regions and clinical behaviors in patients with HR. RESULTS: The brain areas of the HR group with lower fALFF values than HCs were the right orbital part of the middle frontal gyrus (RO-MFG) and right lingual gyrus. In contrast, the values of fALFFs in the left middle temporal gyrus (MTG), left superior temporal pole (STP), left middle frontal gyrus (MFG), left superior marginal gyrus (SMG), left superior parietal lobule (SPL), and right supplementary motor area (SMA) were higher in the HR group. The results of a t-test showed that the average values of fALFFs were statistically significantly different in the HR group and HC group (P<0.001). The fALFF values of the left middle frontal gyrus in HR patients were positively correlated with anxiety scores (r=0.9232; P<0.0001) and depression scores (r=0.9682; P<0.0001). CONCLUSION: fALFF values in multiple brain regions of HR patients are abnormal, suggesting that these brain regions in HR patients may be dysfunctional, which may help to reveal the pathophysiological mechanisms of HR.

Visible and near-infrared planar waveguide structure of polycrystalline zinc sulfide from C ions implantation.

We report the fabrication of a planar waveguide in polycrystalline zinc sulfide by 6.0 MeV C ions implantation with a fluence of 5 × 10¹4 ion/cm² at room temperature. The near-field light intensity profiles in the visible and near-infrared bands are measured by the end-face coupling method with different laser sources. Investigation of the Raman spectra demonstrates that the microstructure of the polycrystalline zinc sulfide has no significant change after C ion implantation. The absorption spectra show that the implantation processes have no influence on the visible and infrared bands.

Waveguide structures for the visible and near-infrared wavelength regions in near-stoichiometric lithium niobate formed by swift argon-ion irradiation.

We report the fabrication of a waveguide structure in a near-stoichiometric lithium niobate crystal using 200-MeV argon-ion irradiation at a fluence of 2 × 10(12) ions/cm2. Guided modes were detected in the visible and near-infrared wavelength regions, suggesting that the waveguide can be used at fiber communications wavelengths. The refractive index profiles of the waveguide were reconstructed from the effective index functions. Micro-Raman spectra recorded in the waveguide layer and the substrate showed that the Li/Nb ratio was preserved in the waveguide layer after swift argon-ion irradiation.

Low-loss optical waveguides and Y-branch splitters in lithium niobate fabricated by MeV oxygen ions with low dose.

Single-mode optical waveguides in LiNbO(3) substrate with loss as low as 0.17dB/cm were fabricated by a multi-energy low-dose ion implantation technology and cumulative annealing treatment. A waveguide Y-Branch splitter was demonstrated. Index profile in waveguide is described based on the ion implantation-induced damage profile, and propagation property in waveguide is simulated. Simulation results show a good consistence with the measured ones.