Laser Sensing and Vision Sensing Smart Blind Cane: A Review.

Laser sensing and vision sensing smart canes can improve the convenience of travel for the visually impaired, but for the present, most of the system functions of laser sensing and vision sensing smart canes are still defective. Guide equipment and smart blind canes are introduced and classified first, and the smart blind canes based on vision sensing, laser sensing and laser vision sensing are investigated, respectively, and the research status of laser vision sensing smart blind canes is sorted out. The advantages and disadvantages of various laser vision sensing smart blind canes are summarized, especially the research development of laser vision fusion as the core of new smart canes. The future development prospects of laser vision sensing smart blind cane are overviewed, to boost the development of laser vision sensing smart blind cane, to provide safe and efficient travel guarantee for the visually impaired.

Research Progress of Wide Tunable Bragg Grating External Cavity Semiconductor Lasers.

In this paper, we review the progress of wide tunable Bragg grating external cavity semiconductor lasers (BG-ECSLs). We concentrate on BG-ECSLs based on the wide tunable range for multicomponent detection. Wide tunable BG-ECSLs have many important applications, such as wavelength-division multiplexing (WDM) systems, coherent optical communications, gas detection and atom cooling. Wide tunability, narrow linewidth and a high side-mode suppression ratio BG-ECSLs have attracted much attention for their merits. In this paper, three main structures for achieving widely tunable, narrow linewidth, high side-mode suppression ratio BG-ECSLs are reviewed and compared in detail, such as the volume Bragg grating (VBG) structure, fiber Bragg grating (FBG) structure and waveguide Bragg grating (WBG) structure of ECSLs. The advantages and disadvantages of different structures of BG-ECSLs are analyzed. The results show that WBG-ECSLs are a potential way to realize the integration, small size, wide tuning range, stable spectral output and high side-mode suppression ratio laser output. Therefore, the use of WBG as optical feedback elements is still the mainstream direction of BG-ECSLs, and BG-ECSLs offer a further new option for multicomponent detection and multi-atoms cooling.

Structural Design of Ocean Temperature and Depth Sensor with Quick Response and High Sensitivity.

The electrical sensing elements used in the traditional XBT (Expendable Bathythermograph) have problems such as low sensitivity and slow response time, and it is difficult to overcome the complex marine environment using the time-depth formula. In this paper, an ocean temperature depth sensor based on brass diaphragm and liquid filling is designed. The stress response time of FBGs with different lengths and the heat transfer time of different liquid materials are compared, and it is found that a fast response of 51 ms can be obtained by using GaInSn liquid for temperature sensing. The center deflection changes of brass diaphragms with different radii are analyzed, and the brass diaphragms with radius and thickness of 10 mm and 1 mm are selected, which still have good elastic properties under the pressure of 5 MPa. The influence of the inner metal shell section radius on the temperature and depth sensitivity is analyzed. When the final section radius is 3 mm, the temperature sensitivity of the sensor is 1.065 nm/°C, the pressure sensitivity is 1.245 nm/MPa, and the response time of temperature and depth is relatively close. Compared with the traditional temperature and depth sensors using empirical formulas for calculation, the data accuracy is improved, and a wide range of sensitivity can be tuned by adjusting the size of the internal metal shell, which can meet the needs of ocean temperature and depth data detection with high sensitivity and fast response time.

Design of a Fiber Bragg Grating Pressure Sensor Based on a Metal Diaphragm and Lever Structure.

In this paper, a pressure sensor based on a metal diaphragm and lever structure is designed, the sensing principle and mechanical structure of this sensor are analyzed and simulated, and its sensitization effectiveness and temperature compensation are verified. The maximum deflections of metal diaphragms of different sizes and materials were compared, and it was found that the square beryllium bronze diaphragm with a thickness of 1 mm and a side length of 20 mm had good elastic properties. The influence of the FBG in different positions of the lever on the center wavelength is analyzed. The sensitivity of the bare FBG is markedly improved under the influence of the two structures of the square elastic diaphragm and the lever, with a typical pressure sensitivity of 3.35 nm/MPa at 3 mm to the left of the lever center. The purpose of temperature compensation is achieved by adding another FBG that measures the temperature, and the sensing sensitivity can be tuned by adjusting the position of the FBG. It can meet the detection needs of a small range and high sensitivity.

[Diagnosis and counseling for a Chinese pedigree affected with autosomal recessive primary microcephaly 5 due to variants of ASPM gene].

OBJECTIVE: To detect potential mutation of the ASPM gene in a Chinese pedigree affected with autosomal recessive primary microcephaly 5 (MCPH5). METHODS: Peripheral venous blood samples were collected from the proband and her parents. Amniotic fluid sample was also collected upon her mother' s subsequent pregnancy. Following extraction of genomic DNA, PCR and Sanger sequencing were carried out to identify potential variants of the ASPM gene. RESULTS: The proband was found to harbor compound heterozygous variants of the ASPM gene, namely c.8214dupT (p.Q2739fs) in exon 18 and c.9541C>T (p.R3181X) in exon 23, which were respectively inherited from her father and mother. The fetus has found to have inherited the c.9541C>T (p.R3181X) variant only. CONCLUSION: The c.8214dupT (p.Q2739fs) and c.9541C>T (p.R3181X) compound heterozygous variants of the ASPM gene probably underlay the pathogenesis of MCPH5 in this patient. Above finding has enabled genetic counseling and prenatal diagnosis for her family.

Retinal Nerve Fiber Layer Thickness and Associations With Cognitive Impairment in Parkinson's Disease.

OBJECTIVE: This study intended to investigate whether retinal nerve fiber layer (RNFL) thickness could become a potential marker in patients with Parkinson's disease with cognitive impairment (PD-CI). METHODS: Fifty-seven PD patients and 45 age-matched healthy controls (HCs) were recruited in our cross-sectional study and completed optical coherence tomography (OCT) evaluations. PD with normal cognition (PD-NC) and cognitive impairment (PD-CI) patients were divided following the 2015 Movement Disorder Society criteria. RNFL thickness was quantified in subfields of the 3.0-mm circle surrounding the optic disk; while a battery of neuropsychiatric assessments was conducted to estimate the Parkinsonism severity. General linear models and one-way ANOVA were adopted to assess RNFL thickness between subgroups with different cognitive statuses; logistic regression analyses were applied to determine the relation between RNFL and PD-CI cases. RESULTS: Compared with HCs, more thinning of the RNFL was observed in the inferior and temporal sectors in PD patients, especially in the PD-CI group. Inferior RNFL thickness was reduced in PD-CI compared with PD-NC patients. Logistic regression analysis found that inferior RNFL thickness was independently associated with PD-CI cases (odds ratio = 0.923, p = 0.014). Receiver operating characteristic analysis showed that the RNFL-involved combined model provided a high accuracy in screening cognitive deficiency in PD cases (area under the curve = 0.85, p < 0.001). CONCLUSION: Reduced RNFL thickness especially in the inferior sector is independently associated with PD-CI patients. Our study present new perspectives into verifying possible indicators for neuropathological processes or disease severity in Parkinsonians with cognitive dysfunction.

[Analysis of HNF1B gene variant in a fetus featuring infantile polycystic kidney disease].

OBJECTIVE: To explore the genetic basis for a fetus featuring infantile polycystic kidney disease (IPKD). METHODS: Following elective abortion, fetal tissue and peripheral blood samples of its parents were collected for the extraction of genomic DNA. Whole exome sequencing was carried out to detect potential variants correlated with the phenotype. RESULTS: The fetus was found to harbor a heterozygous c.1370C>T (p.P457L) variant of the HNF1B gene, which was unreported previously. The same variant was not detected in either parent. CONCLUSION: The heterozygous c.1370C>T (p.P457L) variant of the HNF1B gene probably underlay the IPKD in this fetus. Above finding has enabled genetic counseling and prenatal diagnosis for the family.

Illumination uniformity of an LD and LED hybrid lighting system applied to plant growth.

To develop a current plant lighting source with both a suitable illumination area and high illumination uniformity, we propose a lighting system for plant growth based on the combination of laser diode and LED lighting modes. We added a triangular-prism-shaped base plate element to the previous array type optical structure to increase the light coupling degree and expand the illumination area. The Taguchi method was used in our design and experiment, and the influence of different factors on the illumination uniformity was studied and compared to the lighting effect of a traditional array floor structure. Finally, a plant lighting source with an illumination uniformity of 88.54% and color-mixing uniformity of 84.75% was obtained. Compared to the commonly adopted array structure, this plant lighting source expands the illumination area by 31.03%, which verifies the effectiveness of the scheme.

[Genetic testing and prenatal diagnosis for a family with 10q22.3q23.2 microdeletion].

OBJECTIVE: To carry out genetic testing for a pregnant woman with mild mental retardation, facial dysmorphism, and a history of adverse pregnancies and provide prenatal diagnosis for her. METHODS: Routine G-banded karyotyping and single nucleotide polymorphism microarray (SNP-array) analysis were performed on the couple and amniotic fluid sample. RESULTS: No karyotypic abnormality was found with the couple and amniotic fluid sample. SNP-array analysis showed that the woman has carried a 7.801 Mb microdeletion in 10q22.3q23.2, which involved 18 OMIM genes including CDHR1, BMPR1A, NRG3, GRID1 and LDB3, which are associated with facial abnormalities, developmental retardation, mental retardation and autism. The fetus also carried a 7.819 Mb deletion in the same region, while the father showed no abnormality. CONCLUSION: Both the pregnant woman and her fetus have carried a 10q22.3q23.2 microdeletion, which has provided guidance for her subsequent pregnancy.

Nuclear translocation of ß-catenin induced by E-cadherin endocytosis causes recurrent erosion of diabetic cornea.

Recurrent epithelial erosion and refractory corneal ulcer are the clinical features of diabetic keratopathy (DK), which eventually lead to corneal scar and visual disturbance. In this study, we sought to determine the abnormalities of cell junction in diabetic corneal epithelial cells and the effect of high glucose on the ß-catenin/E-cadherin complex. Corneal histology showed that corneal epithelial cells of high glucose mice were loosely arranged, and the immunohistochemistry showed that the expression of E-cadherin decreased, the levels of ß-catenin increased in nuclear. High glucose-induced degradation and endocytosis of E-cadherin of corneal epithelial cells reduce the formation of ß-catenin/E-cadherin complex and promote the nuclear translocation of ß-catenin. Moreover, high glucose also activated the transcription and expression of matrix metallopeptidase and snail, which interfered with the adhesion of corneal epithelial cells to the basement membrane. These findings reveal that DK is associated with the dissociation of cell junctions. The maintenance of the stability of the ß-catenin/E-cadherin complex may be a potential therapeutic target of refractory corneal ulcers in patients with diabetes.

[Retrospective analysis and mining of data from 10 840 patients undergoing non-invasive prenatal screening].

OBJECTIVE: To retrospectively analyze non-invasive prenatal screening (NIPS) data from two centers. METHODS: The NIPS results of 10 840 samples were analyzed, including 21/18/13 trisomies (T21/T18/T13), sex chromosome and other autosomal aneuploidies, and copy number variants (CNVs). The maternal age, gestational week, body mass index and concentration of free fetal DNA (cffDNA) were also analyzed. RESULTS: The average gestational age of the 10 840 pregnant women was (32.34±5.04) year old, and the average gestational week for NIPS was (17.60±3.55) week. The overall false positive rate for T21/T18/T13 was 0.11%, sensitivity was 100%, specificity was 99.89%, and positive predictive value was 81.5%. The positive predictive values for sex chromosome and other autosomal aneuploidies and CNVs were 56.67%, 11.76% and 83.33%, respectively. The incidence of T21/T18 in the elder women (35 years or elder) was 2.12 times(P<0.01) and 1.81 times (P> 0.05) that of young women. cffDNA was in proportion to gestational week (r = 0.207) and in inverse proportion to body mass index (r = -0.177). It has increased slowly before 15 weeks of gestation and thereafter at a rate of 0.5% per week after the 16th week. CONCLUSION: The performance of NIPS in this study is by large close to the reported in the literature, and the results can provide a reference for further study.

[Prenatal diagnosis and genetic analysis of a fetus with Xp22.12 microduplication].

OBJECTIVE: To provide prenatal diagnosis for a pregnant women carrying a chromosome translocations using single nucleotide polymorphism array (SNP-array). METHODS: The fetus and its parents were subjected to chromosome karyotyping and SNP array analysis. RESULTS: A Xp22.12 microduplication was identified in the fetus with a size of 496.3 kb. Search of literature and database indicated the microduplication to be variant of unclear significance. The phenotypically normal mother has carried a 505.8 kb duplication at the same position. The father was normal for the testing. The couple decided to continue with the pregnancy and gave birth to a healthy girl at full-term. No abnormality was found during the follow-up. CONCLUSION: The Xp22.12 microduplication encompassed part of RPS6KA3 gene, which shows various features of Coffin-Lowry syndrome. Female with Xp22.12 microduplications may be asymptomatic carriers due to X chromosome inactivation. Our case may provide data for delineating the phenotype-genotype correlation of Xp22.12 microduplication.

Poly(lactic-co-glycolic acid) nanoparticle-mediated interleukin-12 delivery for the treatment of diabetic retinopathy.

BACKGROUND: Diabetic retinopathy (DR) is a complication of diabetes that affects the eyes and vision. It is a leading cause of visual impairment and blindness in working-age people. Vascular endothelial growth factor-A (VEGF-A) is a primary initiator and potential mediator of DR. Matrix metalloproteinase-9 (MMP-9) plays a progressive role in the onset and severity of DR. Interleukin-12 (IL-12) is a cytokine of the chemokine family that could reduce the levels of MMP-9 and VEGF-A and suppress tumor angiogenesis. We hypothesize that IL-12 may also have superior therapeutic efficacy against DR. However, protein drugs are prone to degradation by various proteases after drug injection. Therefore, they have short half-lives and low blood concentrations. The objective of this study was to develop IL-12-loaded nanoparticles for long-term and sustained DR treatment. METHODS: IL-12-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (IL-12-PNP) were developed by double emulsion. The characteristics, anti-DR activity, and mechanisms of IL-12-PNP were examined in vitro and in vivo. RESULTS: The nanoparticles had suitable particle size (~132.8 nm), drug encapsulation efficiency (~34.7%), and sustained drug release profile. Compared with IL-12 and blank nanoparticles, IL-12-PNP showed better inhibitory efficacy against VEGF-A and MMP-9 expression in rat endothelial cells and DR mouse retina. Intraocular IL-12-PNP administration significantly reduced retinal damage in DR mice as they presented with increased thickness and decreased neovascularization after treatment. CONCLUSION: These data indicate that IL-12-PNP is an effective drug delivery platform for DR therapy. It restores the thickness and reduces neovascularization of the retinas of DR mice.

Development of high sensitivity 4H-SiC detectors for fission neutron pulse shape measurements.

4H-silicon carbide (4H-SiC) detectors are well suited for measurements of fission neutron pulse shape for their compact size, excellent radiation resistance, and hydrogen free composition. The aim of this study is to improve the 4H-SiC detector's sensitivity to fission neutron pulses. 4H-SiC detectors with varied epilayer thicknesses are fabricated and then tested in the pulsed neutron field of the Chinese Fast Burst Reactor II (CFBR II). The sensitivity of the 4H-SiC detector to the CFBR II neutron pulse is increased by 139.8%, with the enlargement of epilayer thickness from 20 µm to 120 µm. By employing the proton-recoil method, the sensitivity of the 4H-SiC detector to the CFBR II neutron pulse is further increased by 11.6%. With enhanced sensitivity to fission neutron pulses, 4H-SiC detectors are promising devices for high intensity neutron pulse measurements.