All-solid-state ultrafast 2 µm laser with 1.83 W output power.

In this paper, a high-power all-solid-state ultrafast 2 µm mode-locked laser is investigated. The particularity of this laser is the simultaneous utilization of two Tm:YAP crystals in the same resonant cavity, independently pumped by two laser diodes. Using a 20% output coupler, pulses with output power as high as 1.83 W are achieved at a wavelength of 1938 nm with a pulse duration of 1.97 ps and a pulse repetition frequency of 100 MHz. To our knowledge, this mode-locked laser achieves the highest output power of any mode-locked Tm:YAP ultrafast laser reported to date. In addition, this paper provides a new approach to solve the problem of low output power due to multi-mode low-brightness laser diode pumping.

Dissecting the immune discrepancies in mouse liver allograft tolerance and heart/kidney allograft rejection.

The liver is the most tolerogenic of transplanted organs. However, the mechanisms underlying liver transplant tolerance are not well understood. The comparison between liver transplantation tolerance and heart/kidney transplantation rejection will deepen our understanding of tolerance and rejection in solid organs. Here, we built a mouse model of liver, heart and kidney allograft and performed single-cell RNA sequencing of 66,393 cells to describe the cell composition and immune cell interactions at the early stage of tolerance or rejection. We also performed bulk RNA-seq of mouse liver allografts from Day 7 to Day 60 post-transplantation to map the dynamic transcriptional variation in spontaneous tolerance. The transcriptome of lymphocytes and myeloid cells were characterized and compared in three types of organ allografts. Cell-cell interaction networks reveal the coordinated function of Kupffer cells, macrophages and their associated metabolic processes, including insulin receptor signalling and oxidative phosphorylation in tolerance induction. Cd11b+ dendritic cells (DCs) in liver allografts were found to inhibit cytotoxic T cells by secreting anti-inflammatory cytokines such as Il10. In summary, we profiled single-cell transcriptome analysis of mouse solid organ allografts. We characterized the immune microenvironment of mouse organ allografts in the acute rejection state (heart, kidney) and tolerance state (liver).

Molecular Dynamic Simulation of Defective Graphene Nanoribbons for Tension and Vibration.

As deformation and defects are inevitable during the manufacture and service of graphene resonators, comprehensive molecular dynamic (MD) simulations are performed to investigate the vibrational properties of the defective single-layer graphene sheets (SLGSs) during tension. Perfect SLGSs, SLGSs with single vacancy, SLGSs with low-concentration vacancies, and SLGSs with high-concentration vacancies are considered, respectively. The frequencies of the perfect and defective SLGSs at different stretching stages are investigated in detail. The effects of different external forces are also taken into account to study the vibration properties of the defective SLGSs. Results show that the perfect and defective SLGSs both successively perform four stages, i.e., the elastic stage, the yield stage, the hardening stage, and the fracture stage during stretching, and the elastic properties of the SLGSs are insensitive to the vacancy defects, while the ultimate strain is noticeably reduced by the vacancies. The single vacancy has no effect on the vibration properties of SLGS, while the frequency decreases with the increasing vacancy concentration for SLGS at the elastic stage. The frequency of yielded SLGS with a certain vacancy concentration is almost constant even with a varying external force.

Characterization and Function of the Interaction of Angiogenin With Alpha-Actinin 2.

Angiogenin (ANG) is the first human tumor-derived angiogenic protein, which can promote angiogenesis and tumor growth. In a previous study, we identified alpha-actinin 2 (ACTN2), a cytoskeletal protein, as a direct interacting protein with angiogenin. However, the interaction between ANG and ACTN2 was not characterized in detail, which may provide information on the molecular mechanisms of ANG functions. In this study, we mapped the accurate binding domain and sites in ANG and ACTN2, respectively. In ANG, the residues from 83 to 105 are the smallest motif that can bind to ACTN2. We then use site mutation analysis to identify the precise binding sites of ANG in the interaction and found that the 101st residue arginine (R101) represents the critical residue involved in the ANG-ACTN2 interaction. In ACTN2, the residues from 383 to 632, containing two spectrin domains in the middle of the rod structure of ACTN2, play an important role in the interaction. Furthermore, we validated the interaction of ACTN2-383-632 to ANG by glutathione-S-transferase (GST) pull-down assay. In functional analysis, overexpressed ACTN2-383-632 could impair tumor cell motility observably, including cell migration and invasion. Meanwhile, ACTN2-383-632 overexpression inhibited tumor cell proliferation and survival as well. These data suggest that an excess expression of ACTN2 segment ACTN2-383-632 can inhibit tumor cell motility and proliferation by interfering with the interaction between ANG and ACTN2, which provides a potential mechanism of ANG action in tumor growth and metastasis.

Diode-pumped Tm3+,Ho3+ co-doped GAGG mode-locking laser near the 2.1µm wavelength region.

In this paper, a laser diode (LD) pumped passive mode-locking Tm,Ho:GAGG laser based on a semiconductor saturable absorber mirror (SESAM) is reported. By adjusting the group delay dispersions inside the laser cavity and transmissions of the output couplers (OCs), a shortest pulse duration of 10.84 ps at 2089.9 nm is achieved, the average output power is 33.17 mW and the laser runs at a 83.01 MHz repetition rate. A maximum average output power of 66.43 mW is also obtained at 2089.9 nm with a pulse duration of 16.56 ps by using an OC of 3%. To the best of our knowledge, this is the first report on the mode-locking Tm,Ho:GAGG laser.

Highly Stable Passively Q-Switched Erbium-Doped All-Fiber Laser Based on Niobium Diselenide Saturable Absorber.

A saturable absorber (SA) based on niobium diselenide (NbSe2), which is a layered transition metal dichalcogenide (TMD) in the VB group, is fabricated by the optically driven deposition method, and the related nonlinear optical properties are characterized. The modulation depth, saturable intensity, and nonsaturable loss of the as-prepared NbSe2 nanosheet-based SA are measured to be 16.2%, 0.76 MW/cm2, and 14%, respectively. By using the as-fabricated NbSe2 SA, a highly stable, passively Q-switched, erbium-doped, all-fiber laser is realized. The obtained shortest pulse width is 1.49 µs, with a pulse energy of 48.33 nJ at a center wavelength of 1560.38 nm. As far as we know, this is the shortest pulse duration ever obtained by an NbSe2 SA in a Q-switched fiber laser.

Simulation and experimental results of a high-gain two-stage and double-pass off-axis Nd:YVO4 picosecond laser amplifier.

A high-gain two-stage double-pass off-axis Nd:YVO4 picosecond laser amplifier has been developed. The comprehensive influence of crystal doping concentration and pump beam quality on the small-signal gain of the Nd:YVO4 amplifier is theoretically analyzed with a model developed by considering energy transfer upconversion and pump light absorption saturation effect. The thermal effect of Nd:YVO4 crystal with different doping concentrations, undoped end cap lengths, and pump beam quality is investigated as well. Based on the theoretical analysis, a high-gain two-stage and double-pass off-axis Nd:YVO4 amplifier based on picosecond fiber seed source is realized by choosing long-composite low-doping Nd:YVO4 crystal and with high brightness laser diode pumping, delivering a gain of 28 dB and an output pulse energy of 67.5 µJ at a repetition rate of 200 kHz.

Effect of Sleeve Gastrectomy on Glycometabolism via Forkhead Box O1 (FoxO1)/Lipocalin-2 (LCN2) Pathway.

BACKGROUND The mechanism by which sleeve gastrectomy (SG) improves glycometabolism has remained unclear so far. Increasing evidence has demonstrated that bone is a regulator of glucose metabolism, and osteoblast-derived forkhead box O1 (FoxO1) and lipocalin-2 (LCN2) are regulators of energy metabolism. The aim of this study was to investigate whether the FOXO1/LCN2 signaling pathway is involved in the anti-diabetic effect of SG. MATERIAL AND METHODS Insulin resistance was induced in Wistar rats, which were then intraperitoneally injected with streptozotocin to induce a type 2 diabetic state. Levels of fasting blood glucose, serum insulin, HbA1c, and LCN2 were analyzed at corresponding time points after SG and sham surgeries. The expressions of FOXO1, LCN2, and the melanocortin 4 receptor (MC4R) in bone and hypothalamus were detected by immunofluorescence. FOXO1 siRNA was applied to downregulate FOXO1 expression in osteoblasts of rats. The influence of FOXO1 gene on expression of LCN2 was investigated in cultured osteoblasts by western blot and PCR. RESULTS Glucose metabolism in the SG group was significantly improved. The LCN2 expression in bone in the SG group was higher than that in the sham group, whereas FOXO1 expression in the SG group was lower than that in the sham group. The binding rate of LCN2 and MC4R in the hypothalamus was also higher in the SG group compared with that in the sham group. The downregulation of FOXO1 expression in osteoblasts was accompanied by upregulation of LCN2 expression. CONCLUSIONS These results suggest that the FOXO1/LCN2 signaling pathway participates in the anti-diabetic effect of SG.

Application of modified primary closure of the pelvic floor in laparoscopic extralevator abdominal perineal excision for low rectal cancer.

AIM: To introduce a novel, modified primary closure technique of laparoscopic extralevator abdominal perineal excision (LELAPE) for low rectal cancer. METHODS: We retrospectively analyzed data from 76 patients with rectal cancer who underwent LELAPE from March 2013 to May 2016. Patients were classified into the modified primary closure group (32 patients) and the biological mesh closure group (44 patients). The total operating time, reconstruction time, postoperative stay duration, total cost, postoperative complications and tumor recurrence were compared. RESULTS: All surgery was successfully performed. The pelvic reconstruction time was 14.6 ± 3.7 min for the modified primary closure group, which was significantly longer than that of the biological mesh closure group (7.2 ± 1.9 min, P < 0.001). The total operating time was not different between the two groups (236 ± 20 min vs 248 ± 43 min, P = 0.143). The postoperative hospital stay duration was 8.1 ± 1.9 d, and the total cost was 9297 ± 1260 USD for the modified primary closure group. Notably, both of these categories were significantly lower in this group than those of the biological mesh closure group (P = 0.001 and P = 0.003, respectively). There were no differences observed between groups when comparing other perioperative data, long-term complications or oncological outcomes. CONCLUSION: The modified primary closure method for reconstruction of the pelvic floor in LELAPE for low rectal cancer is technically feasible, safe and cost-effective.

Combination of Oxaliplatin and Vit.E-TPGS in Lipid Nanosystem for Enhanced Therapeutic Efficacy in Colon Cancers.

PURPOSE: The main aim of present study was to prepare the oxaliplatin (OXL)-loaded D-α-Tocopherol polyethylene glycol 1000 succinate (TPGS)-based lipid nanoparticles to enhance the anticancer effect in colon cancer cells. METHODS: The nanoparticles were nanosized and spherical shaped and exhibited controlled release kinetics. Flow cytometer and confocal laser scanning microscopy (CLSM) showed a remarkable uptake of nanoparticles in cancer cells in a time-dependent manner. RESULTS: The presence of TPGS remarkably increased the anticancer effect of OXL in HT-29 colon cancer cells. The IC50 value of free OXL was 4.25 µg/ml whereas IC50 value of OXL-loaded TPGS-based lipid nanoparticles (OXL/TLNP) was 1.12 µg/ml. The 3-fold lower IC50 value of OXL/TLNP indicates the superior anticancer effect of nanoparticle-based OXL. Consistently, OXL/TLNP induced a remarkable apoptosis of cancer cells. Approximately, ~52% of cells were in early apoptosis phase and ~13% of cells were in late apoptosis phase indicating the potent anticancer effect of the formulations. The findings from this study provide novel insights into the use of TPGS and lipid nanoparticle together for the better antitumor effect in colon cancers. Future studies will involve the detailed in vitro and in vivo studies on clinically relevant animals.

[Application of lymph node labeling with carbon nanoparticles in laparoscopic colorectal cancer surgery].

OBJECTIVE: To investigate the value of lymph node labeled with carbon nanoparticles in laparoscopic colorectal cancer resection. METHODS: The clinical data of 53 patients received laparoscopic radical colorectal surgeries in our department from March 2014 to July 2014 was retrospectively analyzed.Among these patients, carbon nanoparticles were injected into the periphery of the tumor under colonoscopy 1-3 days before the operation (the nanoparticle group) in 26 patients, while 27 patients received operation directly (the control group).The number of cleared lymph nodes, tiny lymph nodes (<5 mm), dyed lymph nodes, and lymph node metastatic rate were compared between the two groups. RESULTS: The two groups had no statistical difference in basic characteristics; 434 and 340 lymph nodes were dissected in the nanoparticle group and control group respectively.The average number of cleared lymph nodes(16.7 ± 3.2) in the nanoparticle group was significantly higher than that of the control group(12.6 ± 2.3) (P<0.001). Besides, both the average number and ratio of cleared tiny lymph nodes in the nanoparticle group were significant higher than those of the control group (P<0.001). Moreover, the rate of less than 12 detected lymph nodes in the nanoparticle group was markedly lower than that of the control group (0 vs 33.3%, P=0.001).There was no statistical difference in lymph node metastatic rate between the two groups (P=0.693). CONCLUSION: Application of lymph node labeled with carbon nanoparticles in laparoscopic colorectal cancer surgery could instruct lymph nodes dissection, improve lymph node detection rate, reduce tumor residual rate, improve the accuracy of pathological staging, and guide the postoperative adjuvant therapy.