A curvature sensor based on twisted single-mode-multimode-single-mode hybrid optical fiber structure

An optical fiber curvature sensor based on a twisted multimode fiber (MMF) sandwiched between two single-mode fibers (SMF) is proposed and investigated theoretically and experimentally. The measured transmission spectrum exhibits good agreement with theoretical predictions. Compared with a traditional single-mode-multimode-single-mode fiber structure sensor, the proposed configuration offers a higher average curvature sensitivity of -2.42 nm/m -1 over a curvature measurement range of 0-1.7390 m -1 and -7.09 dB/m -1 at an operating wavelength of 1537 nm. The temperature sensitivity of this sensor has been determined as 0.01 nm/°C over a wavelength range of 1535-1550 nm and circa 0.007 dB/°C at the wavelength of 1537 nm, over a measured temperature range of 21-121 °C

Development of marker-free transgenic Jatropha plants with increased levels of seed oleic acid

<p>Abstract</p> <p>Background</p> <p><it>Jatropha curcas </it>is recognized as a new energy crop due to the presence of the high amount of oil in its seeds that can be converted into biodiesel. The quality and performance of the biodiesel depends on the chemical composition of the fatty acids present in the oil. The fatty acids profile of the oil has a direct impact on ignition quality, heat of combustion and oxidative stability. An ideal biodiesel composition should have more monounsaturated fatty acids and less polyunsaturated acids. Jatropha seed oil contains 30% to 50% polyunsaturated fatty acids (mainly linoleic acid) which negatively impacts the oxidative stability and causes high rate of nitrogen oxides emission.</p> <p>Results</p> <p>The enzyme 1-acyl-2-oleoyl-sn-glycero-3-phosphocholine delta 12-desaturase (FAD2) is the key enzyme responsible for the production of linoleic acid in plants. We identified three putative <it>delta </it><it>12 </it><it>fatty acid desaturase </it>genes in <it>Jatropha </it>(<it>JcFAD2s</it>) through genome-wide analysis and downregulated the expression of one of these genes, <it>JcFAD2-1</it>, in a seed-specific manner by RNA interference technology. The resulting <it>JcFAD2-1 </it>RNA interference transgenic plants showed a dramatic increase of oleic acid (> 78%) and a corresponding reduction in polyunsaturated fatty acids (< 3%) in its seed oil. The control <it>Jatropha </it>had around 37% oleic acid and 41% polyunsaturated fatty acids. This indicates that FAD2-1 is the major enzyme responsible for converting oleic acid to linoleic acid in <it>Jatropha</it>. Due to the changes in the fatty acids profile, the oil of the <it>JcFAD2-1 </it>RNA interference seed was estimated to yield a cetane number as high as 60.2, which is similar to the required cetane number for conventional premium diesel fuels (60) in Europe. The presence of high seed oleic acid did not have a negative impact on other <it>Jatropha </it>agronomic traits based on our preliminary data of the original plants under greenhouse conditions. Further, we developed a marker-free system to generate the transgenic <it>Jatropha </it>that will help reduce public concerns for environmental issues surrounding genetically modified plants.</p> <p>Conclusion</p> <p>In this study we produced seed-specific <it>JcFAD2-1 </it>RNA interference transgenic <it>Jatropha </it>without a selectable marker. We successfully increased the proportion of oleic acid versus linoleic in <it>Jatropha </it>through genetic engineering, enhancing the quality of its oil.</p

Effects of Curcumin on Epidermal Growth Factor in Proliferative Vitreoretinopathy

Background/Aims: Proliferative vitreoretinopathy (PVR) is a common refractory eye disease that causes blindness and occurs after retinal detachment or retinal reattachment. Epidermal growth factor (EGF) has been shown to play an important role in the migration and proliferation of retinal pigment epithelium (RPE) cells, which promote PVR. Curcumin inhibits RPE cell proliferation, but it is not known whether it participates in the formation of PVR. Curcumin regulates the biological functions of EGF, which plays important roles in the development of PVR. This study aimed to evaluate the effect of curcumin on the regulation of EGF in PVR. Methods: Rabbit RPE cells were cultured, and EGF expression was detected by immunocytochemistry. MTT assay was conducted to determine cell proliferation induced by different concentrations of EGF. Immunocytochemical staining was used to detect EGF expression after treatment with curcumin at varying concentrations. Real-time PCR (RT-PCR) and western blot analysis were used to detect the concentrations of EGF mRNA and protein after treatment with curcumin. After RPE cells and curcumin were injected into experimental rabbit eyes, the cornea, aqueous humor, lens, and vitreous opacity were observed and recorded simultaneously by indirect ophthalmoscopy, fundus color photography, and B-ultrasonography. The vitreous body was extracted, and the EGF content in the vitreous humor was measured by enzyme-linked immunosorbent assay (ELISA). Results: At each time point (24, 48, and 72 h), cell proliferation gradually increased with increasing EGF concentrations (0, 3, 6, and 9 ng/mL) in a dose-dependent manner. Cell proliferation between EGF concentrations of 9 and 12 ng/mL were no different, which suggested that 9 ng/mL EGF was the best concentration to use to stimulate RPE cell proliferation in vitro. Under all EGF concentrations (0, 3, 6, 9, and 12 ng/mL), RPE cell proliferation increased with time (from 24 to 72 h), suggesting a time–effect relationship. Curcumin downregulated EGF expression in RPE cells, which also indicated time–effect and dose–effect relationships. The best curcumin concentration for the inhibition of EGF expression was 15 µg/mL. RT-PCR and western blot analyses indicated that the EGF mRNA and expression of the protein in RPE cells treated with curcumin significantly decreased with time. Ocular examinations revealed that the vitreous opacity was lower and the proliferative membrane was thinner in the curcumin group compared with the control group. The PVR grade and the incidence of retinal detachment were significantly lower in the experimental group than in the control group. ELISA results showed that the EGF content in vitreous humor was higher in the control group than in the curcumin group. The curcumin and control groups were significantly different at each time point. Conclusion: Curcumin inhibited RPE cell proliferation by downregulating EGF and thus effectively inhibited the initiation and development of PVR

Amplitude analysis of Ds+→π+π−π+D_s^{+} \rightarrow \pi^{+} \pi^{-} \pi^{+}

Utilizing the data set corresponding to an integrated luminosity of $3.19$ fb$^{-1}$ collected by the BESIII detector at a center-of-mass energy of 4.178 GeV, we perform an amplitude analysis of the $D_s^+\to\pi^+\pi^-\pi^+$ decay. The sample contains 13,797 candidates with a signal purity of $\sim$80%. The amplitude and phase of the contributing $\pi\pi$ ${\cal S}$ wave are measured based on a quasi-model-independent approach, along with the amplitudes and phases of the ${\cal P}$ and ${\cal D}$ waves parametrized by Breit-Wigner models. The fit fractions of different intermediate decay channels are also reported.Comment: 14 pages, 6 figure

Measurement of the absolute branching fractions of J/ψ→γη and η decay modes

Based on a data sample of (1.0087±0.0044)×1010 J/ψ events collected by the BESIII detector at the BEPCII accelerator, the absolute branching fraction (BF) of the decay J/ψ→γη is measured with high precision using events in which the radiative photon converts to e+e-. Using the measured absolute BF of J/ψ→γη, the absolute BFs of four dominant η decay modes are measured for the first time. The results are B(J/ψ→γη)=(1.067±0.005±0.023)×10-3, B(η→γγ)=(39.86±0.04±0.99)%, B(η→π0π0π0)=(31.96±0.07±0.84)%, B(η→π+π-π0)=(23.04±0.03±0.54)%, and B(η→π+π-γ)=(4.38±0.02±0.10)%, where the first and second uncertainties are statistical and systematic, respectively. The results are consistent with the world average values within two standard deviation

Narrow Intercondylar Notch and Anterior Cruciate Ligament Injury in Female Nonathletes with Knee Osteoarthritis Aged 41–65 Years in Plateau Region

Background: Few data are available concerning intercondylar notch dimensions in female nonathletes with knee osteoarthritis (OA) in plateau region. The aim of this study was to assess the relation of intercondylar notch morphology to anterior cruciate ligament (ACL) injuries in female nonathletes with knee OA aged 41–65 years from the Chinese Loess Plateau. Methods: The study was conducted on 330 patients with ACL injury (aged 31–65 years; 159 males, 171 females), 141 patients with OA (aged 31–65 years; 59 males, 82 females), and 89 female healthy controls (aged 41–65 years), and this evaluation included identifying the distribution of patients with OA or ACL injury and measuring the intercondylar notch width indexes (NWIs). Results: There was a significant rising trend in patients with OA (the Kellgren and Lawrence grade = 3) with ACL injury (OA-S + ACL) aged 41–65 years, especially in females. We found that the notches of OA-S + ACL had a smaller NWI compared with control and OA without ACL injury (OA-S-only, P = 0.000, 95% confidence interval [CI] = −0.059–−0.030; P = 0.000, 95% CI = −0.049–−0.016). A similar trend was found in notch shape index (NSI), but not in notch depth index and the cross-sectional area. The cutoff of NWI and NSI value was 0.26, and 0.65, and area under the receiver operating characteristic curve was 0.82, and 0.79, respectively. Further study displayed a significant correlation between a reduced NWI and NSI and OA-S + ACL (P = 0.000, χ2 = 14.012; P = 0.000, χ2 = 14.286). Conclusion: A narrower intercondylar notch and a plateau environment are risk factors of predisposing female nonathletes with knee OA to ACL injury aged 41–65 years

The common pathogenesis of nodular goiter in both sexes: An exploration into gene expression and signaling pathways

The past few years have witnessed an increasing incidence of nodular goiter (NG), with a well-documented higher prevalence in females than males. This gender disparity has led research to focus primarily on female subjects, potentially overlooking common pathogenic mechanisms in both sexes. In this study, we investigated the shared pathogenesis of NG in males and females. Utilizing a rat model and RNA sequencing, we identified differentially expressed genes associated with the disease. We further validated these findings in normal human thyroid cells and human papillary thyroid cancer cells. A randomized experiment was conducted with equal numbers of male and female rats divided into control and NG model groups. The NG model was established using propylthiouracil and various assessments such as thyroid ultrasonography, thyroid index, thyroid function, and thyroid histology were performed. Transcriptome analysis revealed numerous upregulated and downregulated genes in both male and female model groups. Key genes like KDR, FLT1, PDGFB, and CAV1, and pathways including PI3K-Akt, MAPK, Ras, fluid shear stress and atherosclerosis, calcium signaling, and Rap1 signaling pathways were linked with the disease. Western blot and immunofluorescence analysis confirmed these findings, which were further supported by cell-based experiments. In conclusion, our findings suggest that abnormal expression of specific genes and pathways leading to irregular cell growth, blood vessel formation, and inflammation may be common factors in the pathogenesis of NG in both males and females