[Clinicopathologic and molecular genetic analysis of secretory carcinoma of salivary gland]

Objective: To investigate the clinicopathologic and molecular genetic features of secretory carcinoma of salivary gland (SCSG). Methods: Six cases of SCSG were collected from Zhejiang Provincial People's Hospital from January 2011 to March 2018. The clinical, histopathological and immunohistochemical features were analyzed and fluorescence in situ hybridization (FISH) was used to detect ETV6 gene rearrangement. Results: Four out of 6 tumors originated in the parotid gland and one of each in the minor salivary glands of soft palate and the buccal mucosa. Grossly, 4 cases were solid and 2 were partially cystic with maximum diameter ranging from 1.0 to 4.0 cm. Microscopically, 5 tumors showed typical features of low grade SCSG with tumor divided by thin fibrous septa into lobules composed of solid acinar, microcystic, follicular and papillary structures with abundant extracellular mucinous secretions. The tumor cells had cuolated or hobnail cytoplasm with low-grade nuclei and scarce mitoses. Perineural invasion was present in 1 case. The remaining tumor showed about 30% of the tumor areas with high-grade transformation characterized by proliferation of a distinct population of anaplastic cells arranged in irregular glandular, small nested and single cell patterns that were surrounded by desmoplastic stroma and invaded into surface mucosa with ulceration. Immunohistochemistry showed that all 6 tumors had diffuse and strong reactivities to S100 protein and cytokeratin 7, and 4 cases showed focal reactivity to gross cystic disease fluid protein 15 (GCDFP15), all were negative for discovered on gist 1 (DOG1), cytokeratin 20, p63 and calponin. High grade transformation cases were analysed, the high grade SCSG components showed a significantly increased Ki-67 index and cyclin D1 positive tumor cells compared to the conventional SCSG components. FISH analyses showed that 4 cases had ETV6 gene rearrangement. Eleven to seventy one months' follow-up showed no evidence of tumor recurrence nor metastasis. Conclusions: SCSG harbors characteristic genetic abnormalities with ETV6 gene rearrangement and typically shows a low grade morphology with occasionally, high grade transformation can be present.

Efficient point-by-point Bragg gratings fabricated in embedded laser-written silica waveguides using ultrafast Bessel beams

We demonstrate highly efficient Bragg gratings written point-by-point by sequential single-pulse ultrashort Bessel laser beams in laser photoinscribed single-mode waveguides in bulk fused silica. The use of chirped non-diffractive Bessel beams determines a strong Bragg resonance in a weak-to-strong transitional regime, augmenting to a record value of 40  dB/cm at 1550 nm in the third order. The Bessel-induced refractive index modulation is negative and localized to sub-micrometer (200 nm) transverse scales. The strong light confinement in Bessel beams ensuring uniform one-dimensional void conditions thus allows for enhanced precision in the Bragg grating waveguide design. We demonstrate flexible fabrication of multiplexed waveguide gratings for multiple and tunable spectral resonances.

First Measurement of Monoenergetic Muon Neutrino Charged Current Interactions

We report the first measurement of monoenergetic muon neutrino charged current interactions. MiniBooNE has isolated 236 MeV muon neutrino events originating from charged kaon decay at rest (K^{+}→μ^{+}ν_{μ}) at the NuMI beamline absorber. These signal ν_{μ}-carbon events are distinguished from primarily pion decay in flight ν_{μ} and ν[over ¯]_{μ} backgrounds produced at the target station and decay pipe using their arrival time and reconstructed muon energy. The significance of the signal observation is at the 3.9σ level. The muon kinetic energy, neutrino-nucleus energy transfer (ω=E_{ν}-E_{μ}), and total cross section for these events are extracted. This result is the first known-energy, weak-interaction-only probe of the nucleus to yield a measurement of ω using neutrinos, a quantity thus far only accessible through electron scattering.

Diversity of the Bacterial Microbiome in the Roots of Four Saccharum Species: S. spontaneum, S. robustum, S. barberi, and S. officinarum

Endophytic bacteria are nearly ubiquitously present in the internal tissues of plants, and some endophytes can promote plant growth. In this study, we sampled the roots of four ancestral species of sugarcane (two genotypes per species) and two sugarcane cultivars, and used 16S rRNA and nifH gene sequencing to characterize the root endophytic bacterial communities and diazotroph diversity. A total of 7,198 operational taxonomic units (OTUs) were detected for the endophytic bacteria community. The endophytic bacterial communities exhibited significantly different α- and β-diversities. From the 202 detected families in the sugarcane roots, a core microbiome containing 13 families was identified. The nifH gene was successfully detected in 9 of 30 samples from the four sugarcane species assayed, and 1,734 OTUs were merged for endophytic diazotrophs. In the tested samples, 43 families of endophytic diazotrophs were detected, and six families showed differences across samples. Among the 20 most abundant detected genera, 10 have been reported to be involved in nitrogen fixation in sugarcane. These findings demonstrate the diversity of the microbial communities in different sugarcane germplasms and shed light on the mechanism of biological nitrogen fixation in sugarcane.

The localization and function of p38α mitogen-activated protein kinase in rat oocytes

P38α mitogen-activated protein kinase (MAPK), which is a member of the canonical MAPK family, is activated in response to various extracellular stresses and plays a role in multiple cellular processes. In this study, we investigated the expression, subcellular localization and functional roles of p38α MAPK during the meiotic maturation of rat oocytes. We found that p38α MAPK phosphorylation (p-p38α MAPK, indicative of p38α MAPK activation) was low at the germinal vesicle (GV) stage, increased 3 hr after germinal vesicle breakdown (GVBD) and maintained its maximum at metaphase I (MI) or metaphase II (MII). The p-p38α MAPK mainly accumulated in the GV and had no obvious expression in the nucleus. From GVBD to MII, p-p38α MAPK was distributed in the cytoplasm around either the chromosomes or the spindle. We used SB203580, an inhibitor of p38α MAPK, to investigate the possible functional role of p38α MAPK during rat oocyte meiotic maturation. Treatment of GV stage oocytes with 20 μM SB203580 blocked p-p38α MAPK activity, and the spindles appeared abnormal. Additionally, the rate of GVBD after 3 hr of culture with 20 μM SB203580 (58.8%) was significantly inhibited compared with the control (82.5%, p < .05), and the polar body extrusion rate after 12 hr of culture with SB203580 was also significantly decreased compared with the control (40.1% vs 73.3%, p < .05). Taken together, these data indicate that p38α MAPK may play a vital role in rat oocyte meiotic maturation.

Vitamin D and gestational diabetes mellitus: a systematic review based on data free of Hawthorne effect

BACKGROUND

Gestational diabetes mellitus (GDM) is an increasingly prevalent disorder, associated with low blood vitamin D level.

OBJECTIVES

To evaluate the relationship between vitamin D and GDM.

SEARCH STRATEGY

EMBASE, MEDLINE, Cochrane Library and China Biology Medicine disc were searched up to May 2017. The references of previous studies were screened.

SELECTION CRITERIA

Observational studies on the relationship between vitamin D and GDM free from Hawthorne effect and randomised controlled trials of vitamin D supplementation during pregnancy for preventing or treating GDM were included.

DATA COLLECTION AND ANALYSIS

Data and information of included articles were extracted by duplicate using piloted tables. Newcastle-Ottawa Scale and Cochrane Handbook were used for quality assessment. Random-effects models were used for meta-analyses. Heterogeneity tests, sensitivity analysis and analysis of publication bias were conducted.

MAIN RESULTS

Eighty-seven observational studies and 25 randomised controlled trials involving 55 859 and 2445 women, respectively, were included. Low blood vitamin D level during pregnancy was associated with a higher risk of GDM (OR 1.850, 95% CI 1.471-2.328). Blood vitamin D level for women with GDM were lower than in the control women. Blood vitamin D level was associated with fasting plasma glucose (FPG) and homeostasis model of assessment for insulin resistance index (HOMA-IR) (r = -0.100 and r = -0.351), whereas the correlation between blood vitamin D level and fasting insulin (FINS) might be concealed by publication bias. Vitamin D intervention during pregnancy could change the blood levels of vitamin D, FINS, FPG, HOMA-IR, glutathione, C-reactive protein and lipid.

CONCLUSIONS

Low blood vitamin D level could increase the risk of GDM, and vitamin D supplementation during pregnancy could ameliorate the condition of GDM.

TWEETABLE ABSTRACT

Low blood vitamin D increases gestational diabetes mellitus (GDM) risk. Vitamin D supplementation ameliorates GDM condition.

Mechanisms of cognitive-behavioral therapy for obsessive-compulsive disorder involve robust and extensive increases in brain network connectivity

Cognitive-behavioral therapy (CBT) is effective for obsessive compulsive disorder (OCD); however, little is understood about its mechanisms related to brain network connectivity. We examined connectivity changes from resting-state functional magnetic resonance imaging data pre-to-post-CBT in 43 OCD participants, randomized to receive either 4 weeks of intensive CBT or 4 weeks waitlist followed by 4 weeks of CBT, and 24 healthy controls before and after 4 weeks of no treatment. Network-based-statistic analysis revealed large-magnitude increases in OCD connectivity in eight networks. Strongest increases involved connectivity between the cerebellum and caudate/putamen, and between the cerebellum and dorsolateral/ventrolateral prefrontal cortices. Connectivity increases were associated with increased resistance to compulsions. Mechanisms of CBT may involve enhanced cross-network integration, both within and outside of classical cortico-striatal-thalamo-cortical regions; those involving cerebellar to striatal and prefrontal regions may reflect acquisition of new non-compulsive goal-directed behaviors and thought patterns. Our findings have implications for identifying targets for enhancing treatment efficacy and monitoring treatment progress.

Dissecting the Molecular Mechanism of the Subcellular Localization and Cell-to-cell Movement of the Sugarcane mosaic virus P3N-PIPO

The coding sequence of P3N-PIPO was cloned by fusion PCR from Sugarcane mosaic virus (SCMV), a main causal agent of sugarcane (Saccharum spp. hybrid) mosaic disease. SCMV P3N-PIPO preferentially localized to the plasma membrane (PM) compared with the plasmodesmata (PD), as demonstrated by transient expression and plasmolysis assays in the leaf epidermal cells of Nicotiana benthamiana. The subcellular localization of the P3N-PIPO mutants P3N-PIPOT1 and P3N-PIPOT2 with 29 and 63 amino acids deleted from the C-terminus of PIPO, respectively, revealed that the 19 amino acids at the N-terminus of PIPO contributed to the PD localization. Interaction assays showed that the 63 amino acids at the C-terminus of PIPO determined the P3N-PIPO interaction with PM-associated Ca²⁺-binding protein 1, ScPCaP1, which was isolated from the SCMV-susceptible sugarcane cultivar Badila. Like wild-type P3N-PIPO, P3N-PIPOT1 and P3N-PIPOT2 could translocate to neighbouring cells and recruit the SCMV cylindrical inclusion protein to the PM. Thus, interactions with ScPCaP1 may contribute to, but not determine, SCMV Pm3N-PIPO’s localization to the PM or PD. These results also imply the existence of truncated P3N-PIPO in nature.

Influence of tumor size on outcomes following pelvic exenteration

OBJECTIVE

Pelvic exenteration (PE) is often the only curative option for locally advanced or recurrent pelvic malignancies. Despite radical surgery, recurrence risk and morbidity remain high. In this study, we sought to determine tumor size effect on perioperative outcomes and subsequent survival in patients undergoing PE.

METHODS

Retrospective chart review was performed for female patients who underwent PE at two comprehensive cancer centers from 2000 to 2015. Demographics, complications and outcomes were recorded. Statistical analyses were performed using chi-square, student's t-test, logistic regression, non-parametric tests, log-rank test, and Cox proportional hazards.

RESULTS

Of 151 women who underwent PE, 144 had available pathologic tumor size. Gynecologic oncology, surgical oncology, and urology performed 84, 29, and 31 exenterations, respectively. Tumor dimensions ranged from 0 to 25.5cm. Perioperative complications, 30-day mortality, reoperation, and readmission rates were not associated with tumor size. Obesity and prior radiation increased risk for major perioperative complication while anterior exenterations decreased risk. Larger tumors were more likely to undergo total pelvic exenteration (OR 1.14; 95%CI 1.03-1.27), have positive margins (OR 1.11; 95%CI 1.02-1.22), and recur (65%, 42% and 20% for tumors >4cm, ≤4cm and no residual tumor respectively, p=0.016). Tumor size >4cm and positive margins were associated with worse overall survival amongst gynecologic oncology patients.

CONCLUSION

Tumor size was not associated with perioperative morbidity. Larger tumors were associated with positive margins, more extensive resection, and worse survival in gynecologic oncology patients. Larger studies are needed to further understand tumor size impact on PE outcomes within specific tumor types.

Withasteroid B from D. metel L. regulates immune responses by modulating the JAK/STAT pathway and the IL-17+ RORγt+ /IL-10+ FoxP3+ ratio

Datura metel L. is a medicinal herb that contains withasteroids and has a wide range of biological activities. We isolated seven withasteroids from the flowers of D. metel L and examined their ability to inhibit immune responses in vitro and in vivo. Among the withasteroids, withasteroid B2 exhibited the strongest inhibitory effect on immune responses comparing B2 with other isolated compounds from D. metel L., including suppressing the differentiation of CD4⁺ T cells by inhibiting the expression and production of T cell lineage-specific master regulators and cytokines and directly suppressing the cytokine-induced Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathways. In the interleukin (IL)-23-induced mouse ear model of skin disease, B2 repressed disease development by inhibiting the expression of proinflammatory mediators in murine ear skin. Moreover, B2 affected the maturation of dendritic cells (DCs) in vitro which, in turn, induced T cell differentiation with an increased regulatory T cell (T_reg ) phenotype and decreased T helper type 17 (Th17) phenotype. This study provides new evidence that B2 might ameliorate chronic inflammatory skin diseases by suppressing pathogenic CD4⁺ T cell differentiation and the IL-17⁺ retinoic-acid-receptor-related orphan receptor gamma t (RORγt)⁺ /IL-10⁺ forkhead box protein 3 (FoxP3)⁺ ratio. These findings suggest that B2 might mediate the therapeutic effects observed in psoriasis patients following treatment with D. metel L.

The influence of connective tissue growth factor on rabbit ligament injury repair

Objectives

The injured anterior cruciate ligament (ACL) is thought to exhibit an impaired healing response, and attempts at surgical repair have not been successful. Connective tissue growth factor (CTGF) is reported to be associated with wound healing, probably through transforming growth factor beta 1 (TGF-β1).

Methods

A rabbit ACL injury model was used to study the effect of CTGF on ligament recovery. Quantitative real-time PCR (qRT-PCR) was performed for detection of changes in RNA levels of TGF-β1, type 1 collagen (COL1), type 2 collagen (COL2), SRY-related high mobility group-box gene9 (SOX9), tissue inhibitor of metalloproteinase-1 (TIMP-1) and matrix metallopeptidase 13 (MMP-13). Expression of related proteins was detected by Western blotting.

Results

The current study showed that CTGF could promote the recovery of an injured anterior cruciate ligament. It can upregulate mRNA and expression of TGF-β1, COL1, COL2, SOX9, and tissue inhibitor of TIMP-1, and downregulate mRNA and expression of MMP-13, suggesting that the curative effect of CTGF on injured rabbit ligaments is through regulation of these cellular factors.

Conclusions

This finding revealed the healing role of CTGF in injured tissues and provides new possibilities of treating injured tissues and wound healing by using CTGF.

Cite this article: X. Sun, W. Liu, G. Cheng, X. Qu, H. Bi, Z. Cao, Q. Yu. The influence of connective tissue growth factor on rabbit ligament injury repair. Bone Joint Res 2017;6:399–404. DOI: 10.1302/2046-3758.67.BJR.2016-0255.R1.

The associations between serum 25-hydroxyvitamin D level and the risk of total fracture and hip fracture

In this meta-analysis, we evaluated the association between serum 25-hydroxyvitamin D (25(OH) vitamin D) level and the risk of total fractures and hip fractures. Low serum 25(OH) vitamin D level is associated with an increased risk of total and hip fractures.

INTRODUCTION

Data on the association between serum 25(OH) vitamin D level and the risk of fractures are conflicting. This study aimed to provide a summary of prospective cohort or nested case-control studies on the association between serum 25(OH) vitamin D level and the risk of total fractures and hip fractures.

METHODS

We identified relevant studies by searching the PubMed, EMBASE, and OVID databases from their inception to June 1, 2016. We included published prospective cohort or nested case-control studies evaluating the associations of serum 25(OH) vitamin D level with the fracture risk. Two reviewers abstracted the data independently. Relative risks (RRs) with 95% confidence intervals (CIs) were derived throughout the whole analysis.

RESULTS

Sixteen prospective cohort studies and three nested case-control studies were included. We found that low serum 25(OH) vitamin D level was significantly associated with the risk of total fractures (RR 1.25, 95% CI 1.06-1.43; I ² = 31.3%, p for heterogeneity = 0.15) and hip fractures (RR 1.48, 95% CI 1.29-1.68; I ² = 0%, p for heterogeneity = 0.51). The hip fracture risk was increased by 40% for each SD decrease in serum 25(OH) vitamin D level (RR 1.40, 95% CI 1.20-1.61; I ² = 0%, p for heterogeneity = 0.51). The per SD decrease in serum 25(OH) vitamin D level was not associated with the increased risk of total fractures (RR 1.14, 95% CI 0.93-1.35; I ² = 63.2%, p for heterogeneity = 0.04).

CONCLUSIONS

Our study suggests that low serum 25(OH) vitamin D level is associated with increased risks of total and hip fractures. In the analyzed studies, the per SD decrease in serum 25(OH) vitamin D level was associated with the hip fracture risk but not with the total fracture risk.

Proton pump inhibitor monotherapy and the risk of cardiovascular events in patients with gastro-esophageal reflux disease: a meta-analysis

BACKGROUND AND PURPOSE

Proton pump inhibitors (PPIs) are commonly used as potent gastric acid secretion antagonists for gastro-esophageal disorders and their overall safety in patients with gastro-esophageal reflux disease (GERD) is considered to be good and they are well-tolerated. However, recent studies have suggested that PPIs may be a potential independent risk factor for cardiovascular adverse events. The aim of our meta-analysis was to examine the association between PPI monotherapy and cardiovascular events in patients with GERD.

METHODS

A literature search involved examination of relevant databases up to July 2015 including PubMed, Cochrane Library, EMBASE, and ClinicalTrial.gov, as well as selected randomized controlled trials (RCTs) reporting cardiovascular events with PPI exposure in GERD patients. In addition, the pooled risk ratio (RR) and heterogeneity were assessed based on a fixed effects model of the meta-analysis and the I² statistic, respectively.

KEY RESULTS

Seventeen RCTs covering 7540 patients were selected. The pooled data suggested that the use of PPIs was associated with a 70% increased cardiovascular risk (RR=1.70, 95% CI: [1.13-2.56], P=.01, I² =0%). Furthermore, higher risks of adverse cardiovascular events in the omeprazole subgroup (RR=3.17, 95% CI: [1.43-7.03], P=.004, I² =25%) and long-term treatment subgroup (RR=2.33, 95% CI: [1.33-4.08], P=.003, I² =0%) were found.

CONCLUSION & INFERENCES

PPI monotherapy can be a risk factor for cardiovascular adverse events. Omeprazole could significantly increase the risk of cardiovascular events and, so, should be used carefully.

Efficacy of statins for osteoporosis: a systematic review and meta-analysis

Our meta-analysis assessed the efficacy of statins on the risk of fracture, bone mineral density (BMD), and the markers of bone metabolism by collecting data from 33 clinical trials. We found that statin treatment was associated with bone metabolism. And statins seemed to be more effective on male patients with osteoporosis. The efficacy of statins for the treatment of osteoporosis has been controversial in previous studies and meta-analyses. Our meta-analysis was conducted to examine in detail the efficacy of statins on osteoporosis. We searched PubMed, Embase, and the Cochrane Library databases for clinical trials from inception to May 2016. We included studies that described the effect of statins on the risk of fracture, BMD, or bone turnover markers. Moreover, we also conducted subgroup analyses according to the skeleton site, patient gender, and length of follow-up. A total of 33 studies which included 23 observational studies (16 cohort studies and 7 case-control studies) and 10 randomized controlled trials (RCTs) were evaluated. These 33 studies included 314,473 patients in statin group and 1,349,192 patients in control group. Statins decreased the risk of overall fractures (OR = 0.81, 95% CI 0.73-0.89) and hip fractures (OR = 0.75, 95% CI 0.60-0.92). Furthermore, the use of statins was associated with increased BMD at the total hip (standardized mean difference (SMD) = 0.18, 95% CI 0.00-0.36) and lumbar spine (SMD = 0.20, 95% CI 0.07-0.32) and improved the bone formation marker, osteocalcin (OC) (SMD = 0.21, 95% CI 0.00-0.42). However, there was no positive effect on vertebral fractures, upper extremity fractures, BMD at the femoral neck, bone-specific alkaline phosphatase (BALP), and serum C-terminal peptide of type I collagen (S-CTX). Also, compared with male subgroups, the effect on female subgroups was only slightly positive or of no statistical significance. Our meta-analysis indicates that statin treatment may be associated with a decreased risk of overall fractures and hip fractures, an increased BMD at the total hip, BMD at the lumbar spine, and OC. Moreover, our results also show that statin treatment may have a greater effect on male patients than on female patients.

Loss of p300 accelerates MDS-associated leukemogenesis

The role that changes in DNA methylation and histone modifications have in human malignancies is poorly understood. p300 and CREB-binding protein (CBP), two distinct but highly homologous lysine acetyltransferases, are mutated in several cancers, suggesting their role as tumor suppressors. In the current study, we found that deletion of p300, but not CBP, markedly accelerated the leukemogenesis ofNup98-HoxD13 (NHD13) transgenic mice, an animal model that phenotypically copies human myelodysplastic syndrome (MDS). p300 deletion restored the ability of NHD13 expressing hematopoietic stem and progenitor cells (HSPCs) to self-renew in vitro, and to expand in vivo, with an increase in stem cell symmetric self-renewal divisions and a decrease in apoptosis. Furthermore, loss of p300, but not CBP, promoted cytokine signaling, including enhanced activation of the MAPK and JAK/STAT pathways in the HSPC compartment. Altogether, our data indicate that p300 has a pivotal role in blocking the transformation of MDS to acute myeloid leukemia, a role distinct from that of CBP.

Different associations between blood pressure indices and carotid artery damages in a community-based population of China

Different blood pressure (BP) indices had varying associations with carotid intima-media thickness (cIMT) and plaques in clinical practice. However, insufficient evidence has focused on this issue, especially in Chinese population. Herein we examined associations of different BP indices with cIMT and plaques cross-sectionally in a community-based atherosclerosis cohort. We qualitatively measured cIMT and plaques, and also measured central systolic blood pressure and brachial systolic blood pressure (baSBP), from which pulse pressure (PP), and second PP (PP2) were calculated. Logistic multivariate regression was used to assess the associations with BP indices and carotid artery hypertrophy (increased cIMT) and the extent of atherosclerosis (presence of plaques). Each BP index was significantly and independently associated with increased cIMT and plaques except the association of baSBP with plaques. When every two BP indices were put into one model, brachial pressure indices were associated with increased cIMT independently of central pressures, whereas the association between central pressure indices and plaque presence were stronger than those of brachial pressures. In addition, SBP indices were associated with increased cIMT independently of PP indices, whereas PP indices were more strongly related to plaques. In conclusion, central and PP indices might be associated with plaques; however, brachial and SBP indices might be associated with increased cIMT. Nevertheless, whether these BP indices predict increased cIMT and plaque progression warrants further longitudinal and laboratory studies.

Note: Application of a novel 2(3HUS+S) parallel manipulator for simulation of hip joint motion

In the paper, a novel 2(3HUS+S) parallel manipulator, which has two moving platforms, is proposed. The parallel manipulator is adopted to simulate hip joint motion and can conduct an experiment for two hip joints simultaneously. Motion experiments are conducted in the paper, and the recommended hip joint motion curves from ISO14242 and actual hip joint motions during jogging and walking are selected as the simulated motions. The experimental results indicate that the 2(3HUS+S) parallel manipulator can realize the simulation of many kinds of hip joint motions without changing the structure size.

Graphene-clad microfibre saturable absorber for ultrafast fibre lasers

Graphene, whose absorbance is approximately independent of wavelength, allows broadband light–matter interactions with ultrafast responses. The interband optical absorption of graphene can be saturated readily under strong excitation, thereby enabling scientists to exploit the photonic properties of graphene to realize ultrafast lasers. The evanescent field interaction scheme of the propagating light with graphene covered on a D-shaped fibre or microfibre has been employed extensively because of the nonblocking configuration. Obviously, most of the fibre surface is unused in these techniques. Here, we exploit a graphene-clad microfibre (GCM) saturable absorber in a mode-locked fibre laser for the generation of ultrafast pulses. The proposed all-surface technique can guarantee a higher efficiency of light–graphene interactions than the aforementioned techniques. Our GCM-based saturable absorber can generate ultrafast optical pulses within 1.5 μm. This saturable absorber is compatible with current fibre lasers and has many merits such as low saturation intensities, ultrafast recovery times, and wide wavelength ranges. The proposed saturable absorber will pave the way for graphene-based wideband photonics.

Effects of Methyl Mercury Chloride on Rat Hippocampus Structure

The objective of this study is to investigate the impacts of Methyl Mercury Chloride (MMC) on cognitive functions and ultrastructural changes of hippocampus in Sprague Dawley (SD) rats. Thirty healthy 20-day-old male SD rats weighing 30-40 g were randomly divided into three groups to receive daily injections. Two different dose levels were used: 4 mg/kg as high dose (H-MMC) and 2 mg/kg as low dose (L-MMC).The control group received 4 mg/kg saline solution (N-NaCl). After daily subcutaneous injection for 50 days, 6-day Morris water maze tests were used to assess the learning and memory functions of the rats. After a 5-day continuous training, spatial probe tests were conducted of times and paths crossing to the target quadrant on the 6th day. After the rats were euthanized, their hippocampus sections were stained with hematoxylin and eosin and analyzed under bothoptical microscope and electron microscope. The time H-MMC group spent in finding platform was significantly longer as compared toN-NaCl group on day 2 to day 5 and L-MMC group on day 4 to day 5. The number of crossing times of H-MMC group to the target quadrant was 0.63 ± 0.74, which is much lower than C-NaCl group (3.13 ± 1.56) with P value <0.05. No statistically significant difference in crossing times was found between L-MMC and C-NaCl groups. For H-MMC group, decreasing number of neurons and disorganized nerve cells were examined under light microscope. Swelling and dissolution of Golgi complex were examined under electron microscope, along with endoplasmic reticulum expansion and cytoplasmic edema. Mild cytoplasmic edema was found in L-MMC group. MMC can cause cognitive impairment in terms of learning and memory in SD rats. Additionally, it can also cause changes in the ultrastructure of neurons and morphological changes in the hippocampus, causing significant damage.