Timing jitter reduction of passively Q-switched solid-state lasers by coupling resonance between pumping and firing rates

The coupling resonance between pumping and firing rates is originally proposed to achieve the timing jitter reduction of a Nd:YVO₄ laser passively Q-switched with a saturable absorber. When the pumping rate is higher than the spontaneous emission rate, it is experimentally confirmed that the pulse firing rate can be fractionally locked with the pumping rate by controlling the pump power. The locking characteristics of the firing rate display a variety of complex plateaus that can be excellently manifested with the sine-circle map. From numerical analyses, the coupling strength can be verified to be effectively enhanced by reducing the duty cycle of the pumping rate.

[Effects of Huoxiang Zhengqi Oral Liquid on intestinal barrier function in rats with dampness obstructing spleen-stomach syndrome]

The aim of this paper was to investigate the effect of Huoxiang Zhengqi Oral Liquid on intestinal barrier functions in rats with dampness obstructing spleen-stomach syndrome and primarily explore the mechanism. The rat model of dampness obstructing spleen-stomach syndrome was established, and then the modeled rats were randomly divided into the model control group, Huoxiang Zhengqi Oral Liquid high and low dose groups, and natural recovery group according to gender and body weight, with 10 rats in each group. Another 10 rats were taken as blank control group. After each group received the corresponding treatment for 7 days, rat serum was isolated. D-lactic acid content was detected by the MTT method, and diamine oxidase(DAO) activity was detected by the rate method. Colon tissues of the rats were isolated to detect Na~+-K~+-ATPase activity and Ca~(2+)-Mg~(2+)-ATPase activity by phosphate determination method, glutathione peroxidase(GSH-Px) activity was detected by spectrophotometry, catalase(CAT) activity was detected by ammonium molybdate, superoxide dismutase(SOD) activity was detected by hydroxylamine, the expression of occludin protein and ZO-1 protein was detected by immunofluorescence, and the expression levels of occludin protein and ZO-1 protein were detected by Western blot. RESULTS:: showed that low dose Huoxiang Zhengqi Oral Liquid could improve the body weight, diet, stool and urine state of rats with dampness obstructing spleen-stomach syndrome obviously. The D-lactic acid content and the DAO activity in the serum of rats with dampness obstructing spleen-stomach syndrome were reduced obviously. The activities of Na~+-K~+-ATPase, Ca~(2+)-Mg~(2+)-ATPase, GSH-Px, CAT and SOD in rat colon tissues were increased obviously. The occludin proteins and ZO-1 protein expression levels in rat colon tissues were raised obviously. The differences in the above indexes between Huoxiang Zhengqi Oral Liquid group and the model control group were statistically significant(P<0.05). Huoxiang Zhengqi Oral Liquid could effectively restore the intestinal barrier function in rats with dampness obstructing spleen-stomach syndrome and its mechanism may be related to the repair of intestinal mechanical barrier function.

Criterion for optimizing high-power acousto-optically Q-switched self-Raman yellow lasers with repetition rates up to 500 kHz

The criterion for optimizing the high-power acousto-optically ${Q}$Q-switched self-Raman yellow laser is originally explored for the repetition rate within 100-500 kHz. The minimum allowed value for the gate-open time is experimentally verified to be determined by the pulse buildup time. By using the minimum allowed gate-open time, the highest conversion efficiency can be achieved to raise the output power by approximately 20% in comparison with the conventional results. At a repetition rate of 200 kHz, the maximum output power at 588 nm can be up to 8.8 W at an incident pump power of 26 W. Furthermore, a practical formula is developed to accurately calculate the threshold pump power as a function of the gate-open time for a given repetition rate.

Compact efficient high-power triple-color Nd:YVO4 yellow-lime-green self-Raman lasers

A novel, to the best of our knowledge, approach is developed to realize a high-power compact efficient yellow-lime-green triple-color ${\rm Nd}:{{\rm YVO}_4}$Nd:YVO₄ self-Raman laser. The 588 nm yellow laser, the 559 nm lime laser, and the 532 nm green laser are converted from the 1064 nm fundamental wave and the 1176 nm Stokes Raman field. The simultaneous three-color operation is accomplished with three stages to step-by-step generate the 588 nm, 559 nm, and 532 nm lasers by using three different lithium triborate (LBO) crystals. By tuning the temperature of each individual LBO crystal, the 588 nm, 559 nm, and 532 nm output powers can be nearly the same and concurrently up to 2.4 W at the incident pump power of 30 W, corresponding to a conversion efficiency of 24% for the total output power.

[Therapy-related myeloid neoplasms after successful treatment for acute promyelocytic leukemia: a report of four cases and literature review]

目的

探讨急性早幼粒细胞白血病（APL）患者继发治疗相关性髓系肿瘤（t-MN）的临床特点、诊断、治疗及预后。

方法

回顾性分析中国医学科学院血液病医院2012年10月至2019年1月收治的4例APL继发t-MN患者的临床资料，并进行相关文献复习。

结果

4例APL继发t-MN患者均为女性，中位年龄42（40~53）岁，3例接受了以维甲酸（ATRA）+亚砷酸（ATO）为基础联合蒽环/蒽醌类药物±阿糖胞苷的前期诱导缓解及巩固治疗方案，1例采用了ATRA联合蒽环/蒽醌类药物±阿糖胞苷的治疗方案，均没有使用烷化剂。在APL获得完全缓解（CR）后40~43个月出现t-MN，其中治疗相关性骨髓增生异常综合征（t-MDS）1例，治疗相关性急性髓系白血病（t-AML）3例，出现t-MN时PML-RARα融合基因均为阴性。3例t-AML患者接受了2~4个疗程再诱导治疗，其中有1例t-AML患者在获得CR后行异基因造血干细胞移植（allo-HSCT），1例t-MDS患者接受了去甲基化治疗。中位随访54.5（48~62）个月，2例t-AML患者死亡，出现t-MN后中位生存期为12（5~18）个月。1989至2018年文献共报道63例APL继发t-MN病例，与本次报道的4例汇总分析，67例患者中男27例，女40例；中位年龄为52.5（15~76）岁；中位潜伏期39（12~168）个月，确诊t-MN后中位生存时间为10（1~39）个月。

结论

APL继发t-MN较为少见，目前缺乏有效的防治措施，预后不佳，在随访过程中（尤其是获得CR后39个月左右）若出现病情变化，应警惕t-MN的发生，对此类患者应尽快明确疾病的变化，给予合理的治疗。

[Eltrombopag for the treatment of primary immune thrombocytopenia in 23 pediatric patients]

目的

评估艾曲泊帕治疗儿童原发免疫性血小板减少症（ITP）的疗效和不良反应。

方法

回顾性分析2015年5月至2019年3月接受艾曲泊帕治疗的23例儿童ITP患者临床资料。

结果

23例患者中，男11例，女12例，中位年龄11（2~17）岁。新诊断ITP 4例（17.39%），持续性ITP 8例（34.78%），慢性ITP 11例（47.83%）。艾曲泊帕中位起始剂量为25.0（12.5~50.0）mg/d。基线中位血小板计数为14（2~82）×10⁹/L，治疗后第2周（23例）、第4周（23例）、第3个月（16例）、第6个月（11例）的中位血小板计数分别为40（4~170）×10⁹/L、20（4~130）×10⁹/L、60（4~110）×10⁹/L、70（18~160）×10⁹/L，均高于基线水平（z=-3.440，P=0.001；z=-1.964，P=0.049；z=-4.339，P<0.001；z=-5.794，P<0.001）。7例（30.43%）患者的起效时间≤7 d，10例（43.48%）患者的起效时间≤2周，总有效率为60.87%（14/23）。<6岁（6例）、6~12岁（10例）、13~17岁（7例）组的总有效率分别为33.33%（2/6）、60.00%（6/10）、85.71%（6/7），组间比较差异均无统计学意义（P>0.05）。23例患者基线WHO出血评分0、1、2级分别有4、12、7例，治疗后分别为13、7、3例，出血症状得到明显改善（χ²=7.558，P=0.006）。治疗过程中发生转氨酶、胆红素增高各4例，轻度恶心、呕吐及头晕各1例，对治疗均未造成影响。

结论

艾曲泊帕作为二线用药治疗儿童ITP疗效及耐受性均较好。

Integral-based parallel algorithm for the fast generation of the Zernike polynomials

The integral representation of the Zernike radial functions is well approximated by applying the Riemann sums with a surprisingly rapid convergence. The errors of the Riemann sums are found to averagely be not exceed 3 ×10^-14, 3.3×10^-14, and 1.8×10^-13 for the radial order up to 30, 50, and 100, respectively. Moreover, a parallel algorithm based on the Riemann sums is proposed to directly generate a set of radial functions. With the aid of the graphics processing units (GPUs), the algorithm shows an acceleration ratio up to 200-fold over the traditional CPU computation. The fast generation for a set of Zernike radial polynomials is expected to be valuable in further applications, such as the aberration analysis and the pattern recognition.

Origin of continuous curves and dotted spots in laser transverse modes with geometric structures

The transverse structures of geometric modes in degenerate laser resonators with large astigmatism are systematically investigated by starting from the Gaussian wave packet formulation with ray-wave connections. The overlapping degree D between Gaussian wave packets is derived as an analytic expression that manifests the critical overlapping with D=1. The transverse patterns are confirmed to display a structure of continuous curves or dotted spots, depending on D>1 or D<1, respectively. A thorough comparison between experimental results and numerical calculations is performed to validate the theoretical analysis.

Ionization-induced adiabatic soliton compression in gas-filled hollow-core photonic crystal fibers

We investigate in the experiments the ionization-induced adiabatic soliton compression process in a short length of He-filled single-ring photonic crystal fiber. We observe that the plasma-driven blueshifting solitons show little residual light near the pump wavelength in a certain pulse energy region, leading to a high-efficiency frequency upconversion process. In contrast, at high pulse energy levels, we observe that the quality of the frequency upshifting process is impaired due to the existence of a dynamical loss channel induced by the coupling of the soliton to linear modes near the pump wavelength. In addition, through adjusting the input pulse energy, the central wavelength of blueshifting solitons can be continuously tuned over 300 nm. These experimental results, confirmed by numerical simulations, not only offer a deep insight into ionization-induced soliton-plasma dynamics in gas-filled hollow-core photonic crystal fibers, but also develop highly tunable ultrafast light sources at visible wavelengths, which may have many applications in ultrafast spectroscopy.

Generalized wave-packet formulation with ray-wave connections for geometric modes in degenerate astigmatic laser resonators

The parametric equations for periodic rays in degenerate astigmatic laser resonators are derived in a generalized way. The derived parametric equations clearly reveal the formation of Lissajous geometric modes with phase variation along the propagation. Using the representation of a quantum coherent state, a generalized wave-packet formula is derived to connect with the periodic rays of geometric modes. The derived wave-packet formula is not only validated through comparing with various experimental patterns, but also is directly exploited to manifest the spatial asymmetries of Lissajous lasing modes due to a highly transmissive output coupler.

The Anticancer Effects of Paeoniflorin and Its Underlying Mechanisms

Paeoniflorin (PF) is an important pharmacological component of some Chinese traditional herbal formulas, such as Bai Shao, Chi Shao, and Dan Pi, which have been clinically used for centuries. Although many experimental studies have explored a wide range of pharmacological properties of PF, including anticancer, anti-inflammatory, antioxidant, immunoregulatory, and prevention of insulin resistance, there is no review to describe these reported effects systematically, especially the antitumor effect and the underlying mechanisms. In this review, we summarize the recent progress on the anticancer profiles both in vitro and in vivo of PF. Moreover, we highlight the integrated molecular mechanisms of PF and contemplate its future prospects as a potential anticancer drug.

Operating behavior of micro-LEDs on a GaN substrate at ultrahigh injection current densities

Near-ultraviolet micro-LEDs with different diameters were fabricated on GaN substrates. The electroluminescence and the light output power-current density and current density-voltage relationships were measured. A saturated current density of 358 kA/cm² was achieved with a 20 µm LED. The ideality factor curves showed steps and peaks when the injection current density was increased from 20 to 150 kA/cm² and an abnormal efficiency increase. The transport and recombination processes of micro-LEDs at high injection current densities were simulated, and the many-body effect and phase space filling in the integrated quantum drift-diffusion model were considered. Serious current crowding was observed above 100 kA/cm², even for the 20 µm LED.

Analysis of Pelvic Fracture Healing Status in 198 Cases

Abstract

Objective To analyze the relationship between the number of pelvic ring fractures, the location of fracture and Tile type of pelvic fracture and pelvic fracture healing status. To discuss how to understand the pelvic malunion, severe pelvic malunion and bony pelvis deformity （destruction） in Classification of the Impairment Related to Injury. Methods One hundred and ninety-eight cases of evaluation of body impairment class of pelvic fracture caused by traffic accident accepted by Zhongcheng Institute of Forensic Science in 2016 were collected. The cases were statistically analyzed in terms of the distribution of the number of pelvic ring fracture, the location of pelvic ring fracture and Tile type of pelvic fracture in various healing statuses. Results There were 16 cases without pelvic ring fracture, 18 cases of single pelvic ring fracture, 91 cases of 2 pelvic ring fractures, 73 cases of 3 or more pelvic ring fractures, 136 cases of anterior or posterior pelvic ring fractures, 46 cases of simultaneous anterior and posterior ring fractures. There were 34 cases of Tile A type, 130 cases of Tile B type and 24 cases of Tile C type. Statistical analysis results showed that, the differences in distribution of the number of pelvic ring fracture, the location of pelvic ring fracture and Tile type of pelvic ring fracture in various healing statuses had statistical significance （P<0.05）. Conclusion In determination of the healing status of pelvic fracture, preliminary judgment can be made by using the number of pelvic ring fracture, status of pelvic ring fracture and Tile type of pelvic fracture. Caution is required when dealing with single pelvic fractures （including dislocations）, and determining the destruction of bony pelvis.

Exploring the formation of thermally detuned transverse patterns in a broad-area square VCSEL

The formation of thermally detuned transverse patterns of a broad-area square-aperture vertical-cavity surface-emitting laser (VCSEL) via cryogenic cooling is explored. It is found that the transverse wave vector gradually rotates from the horizontal or vertical direction to the diagonal direction of the square boundary as the transverse mode order increases. A model based on the quantum billiards with a finite potential well is developed to emulate the transition behavior of lasing modes. Combining the effective modal gain analysis with the response wave function of driven finite potential billiards, all experimental lasing patterns under different operation temperatures are well reconstructed.

Wave representation for asymmetric elliptic vortex beams generated from the astigmatic mode converter

An analytical wave representation is derived to express the asymmetric elliptic vortex beams generated by using an astigmatic mode converter to transform the asymmetric Hermite-Gaussian modes. The effect of the spatial asymmetry on the elliptic vortex beam can be straightforwardly considered in the analytical wave representation. A detailed comparison with experimental intensity patterns and phase structures is made. The good agreement between experimental results and theoretical analyses confirms the characterization and generation of the asymmetric elliptic vortex beams.

Continuously wavelength-tunable blueshifting soliton generated in gas-filled photonic crystal fibers

We experimentally report the generation of wavelength-tunable blueshifting soliton in the visible spectral region through a gas-filled single-ring photonic crystal fiber (SR-PCF). In particular, in a He-filled SR-PCF, we observed a sharp narrow-band spectral peak at the first resonant spectral region of the SR-PCF, which results from phase-matched nonlinear processes. To the best of our knowledge, this is the first time investigating the influence of the core-cladding resonance on the blueshifting soliton. In addition, when Ar gas was filled into the SR-PCF, some interference fringes on the blueshifting soliton were observed at high pulse-energy levels due to plasma-induced pulse fission. These two experimental observations are confirmed by numerical simulations. Furthermore, through properly adjusting input pulse energy, we found that the blueshifting soliton can obtain a high conversion efficiency (∼84%) and its wavelength can be tuned over hundreds of nanometers (∼240  nm).

Efficient high-power dual-wavelength lime-green Nd:YVO4 lasers

An efficient high-power dual-wavelength lime-green Nd:YVO₄ self-Raman laser is inventively developed by using two different lithium triborate (LBO) crystals. The first and second LBO crystals are employed to generate the 559 nm lime and 532 nm green lasers, respectively. The temperature of the first LBO crystal is fixed at the optimal phase matching, whereas the temperature of the second LBO crystal is tuned to flexibly control the relative strengths between the 532 and 559 nm waves. When the temperature of the second LBO crystal is set for the maximal total output power, the 532 and 559 nm output powers, respectively, are 7.1 and 2.9 W at a pump power of 31.6 W, corresponding to a conversion efficiency of 31.6%. When the temperature is controlled for the balanced output, the 532 and 559 nm powers, respectively, are 4.3 and 4.2 W at a pump power of 31.6 W, corresponding to a conversion efficiency of 26.9%.

[The incidence and risk factors for thrombosis in primary immune thrombocytopenia]

目的

探讨原发免疫性血小板减少症（ITP）患者血栓发生情况及相关危险因素。

方法

对2005年12月至2017年12月在中国医学科学院血液病医院血栓止血中心住院治疗的3 225例ITP患者进行回顾性分析。

结果

共46例患者（1.43%）发生血栓事件，中位发病年龄为54（26~83）岁，成人患者中>40岁人群血栓发生率明显高于40岁以下人群[3.37%（40/1 187）对0.58%（6/1 030），P=0.000]。男、女性患者血栓发生率差异无统计学意义[1.53%（20/1309）对1.36%（26/1 916），P=0.187]。动脉血栓的发生率高于静脉血栓[1.12%（36/3 225）对0.22%（7/3 225），P=0.000]。82.61%（38/46例）患者发生血栓时PLT<100×10⁹/L。吸烟、高血压病、糖尿病及脾切除是ITP患者发生血栓的危险因素（P值分别为0.232、0.531）；糖皮质激素、TPO治疗患者治疗在有无血栓事件的两组间比较差异无统计学意义（P值分别为0.064、0.075、0.531）。

结论

对于中国人群，ITP疾病本身可能也是一种可伴发血栓的免疫性疾病，即使血小板水平低下仍可发生血栓事件；且具有明显的年龄分布特点；吸烟史、高血压病、糖尿病史及脾切除是发生血栓的危险因素。

Exploring elliptical vortex beams with the spatial damping effect

A general integral formula is analytically derived to represent the wave function of elliptical vortex modes. The derived formula can be straightforwardly employed to take account of spatial damping to explore vortex structure. Spatial damping is found to cause the central degenerate singularity of the circular vortex mode to be split into several singularities with different topological charges. For the non-circular vortex beam, the influence of spatial damping on the distribution of singularities is not significant. Theoretical analyses are confirmed to agree very well with the experimental measurements.

[The effects of different activators on the release curve of human platelet-rich plasma]

Objective: To compare and analyze the effects of different activators on the release curve of TGF-β(1) and PDGF-AB in platelet rich plasma(PRP). Methods: A total of 36 ml peripheral venous blood was obtained from 10 healthy adult volunteers, and the PRP was made by secondary centrifugation. The platelet activator was made by bovine thrombin 1 000 U in 1 ml 10% calcium chloride solution. The Thrombin-PRP group was made by PRP and the activator in a ratio of 10∶1.The Calcium chloride-PRP group was made in a ratio of 10∶1 by PRP and 10% calcium chloride solution instead. The fresh whole blood(whole blood group) and inactived PRP(PRP group) were used as the control groups. The 4 groups were incubated in warm water of 37 ℃ for 0, 1, 8, 24,72 and 168 h. A quantitative sandwich enzyme-linked immunosorbent assays(ELISA) was used to examine the amount of TGF-β(1) and PDGF-AB in different time points of each group. The release curves of TGF-β(1) and PDGF-AB were based on afore-mentioned data, and then comparisons of the release curves of TGF-β(1) and PDGF-AB in different groups were performed by repeated measurement variance analysis. Results: (1)The levels of TGF-β(1) and PDGF-AB in the whole blood group and the PRP group continued to increase within 168 h. PRP immediately formed into a gel after mixture with thrombin combined and calcium chloride, and the concentrations of TGF-β(1) and PDGF-AB reached the peak in 1 h after activation; increased from (42±21)ng/ml and (77±18)ng/ml to (84±21)ng/ml and (124±35)ng/ml, respectively, and then decreased gradually. The release curve was direct and rapid. The PRP became a gel state in approximate 1 h after mixture with calcium chloride, and the concentrations of TGF-β(1) and PDGF-AB were slowly rising and remained high at 168 h. (2)The AUC(0-168h) of TGF-β(1) and PDGF-AB in the PRP group was higher than that in the whole blood group (all P<0.05) , and the AUC(0-168h) of TGF-β(1) in the Calcium chloride-PRP group was higher than that in the Thrombin-PRP group(Z=-2.26, P<0.05).However, there was no significant difference in the AUC(0-168h) of PDGF-AB between the Calcium chloride-PRP group and the Thrombin-PRP group(Z=-1.512, P=0.131). Conclusion: Using calcium chloride as activator can get a higher release concentration of TGF-β(1) and PDGF-AB and a longer release time, with the largest area under the curve.

Efficient high-power continuous-wave lasers at green-lime-yellow wavelengths by using a Nd:YVO4 self-Raman crystal

Efficient high-power continuous-wave Nd:YVO₄ visible lasers at versatile wavelengths of 532 (green), 559 (lime), and 588 nm (yellow) are demonstrated to be achieved by using the identical cavity mirrors and gain medium. A dichroic coating is deposited on one end surface of the gain medium to gather the backward green-yellow emission. The green, lime, and yellow outputs are individually optimized by using different phase-matched lithium triborate (LBO) crystals for second harmonic generation (SHG) of the fundamental field, sum frequency generation (SFG) of the fundamental and the stimulated Raman fields, and SHG of the stimulated Raman field, respectively. At a pump power of 31.6 W, the output powers at 532, 559, and 588 nm can be up to 6.8, 5.4, and 3.1 W. The high efficient and compact Nd:YVO₄ lasers at green-lime-yellow wavelengths can be potentially beneficial to future applications in retinal photocoagulation.

Intratumoral IL17-producing cells infiltration correlate with antitumor immune contexture and improved response to adjuvant chemotherapy in gastric cancer

BACKGROUND

Tumor IL17-producing (IL17A+) cells infiltration has different prognostic values among various cancers. The objective of this study was to assess the effect of IL17A+ cells in gastric cancer.

PATIENTS AND METHODS

The study included two patient cohorts, the Cancer Genome Atlas cohort (TCGA, n = 351) and the Zhongshan Hospital cohort (ZSHC, n = 458). The TCGA and ZSHC were used for mRNA-related and cells infiltration-related analyses, respectively. The roles of IL17A mRNA and IL17A+ cells in overall survival (OS), response to adjuvant chemotherapy (ACT), and immune contexture were evaluated. Another independent cohort was included to identify the correlation between mRNA of IL17A and IL17A+ cells infiltration (the preliminary Zhongshan Hospital cohort, PZSHC, n = 21).

RESULTS

The infiltration of IL17A+ cells was positively correlated with the expression of IL17A mRNA (Spearman's ρ = 0.811; P < 0.001). High IL17A mRNA expression and intratumoral IL17A+ cells were correlated with improved OS and remained to be significant after adjusted for confounders. Patients with TNM II/III disease whose tumor present higher intratumoral IL17A+ cells or lower peritumoral IL17A+ cells can benefit more from ACT. Elevated IL17A mRNA expression and increased intratumoral IL17A+ cells infiltration was associated with more antitumor mast cells and nature killer cells infiltration and less pro-tumor M2 macrophages infiltration. High IL17A mRNA expression represented a Th17 cells signature and immune response process and was correlated with increased cytotoxic GZMA, GZMB, IFNG, PRF1, and TNFSF11 expression.

CONCLUSIONS

IL17A mRNA expression and intratumoral IL17A+ cells infiltration were correlated with antitumor immune contexture. IL17A+ cells infiltration could be used as an independent prognostic biomarker for OS and predictive biomarker for superior response to ACT, and further prospective validation needs to be conducted.

Generating high-power asymmetrical Laguerre-Gaussian modes and exploring topological charges distribution

We employ an off-axis pumped Nd:YVO₄ laser and control the reflectance of output coupler to directly generate asymmetrical Hermite-Gaussian (HG) modes with various transverse orders. By using an astigmatic mode converter, the generated asymmetrical HG modes are straightforwardly transformed into asymmetrical Laguerre-Gaussian (LG) modes with a crescent-like shape. The average output power of all the crescent-shaped LG modes can exceed 1W at the pump power of 4W. Furthermore, experimental results are theoretically verified by resonant modes derived from the inhomogeneous Helmholtz equation with the localized source distribution. Theoretical resonant modes are also used to explore the dependence of the phase structures of LG modes on the system loss. As the loss increases, it is found that the singularities at the origin will be rearranged and new singularities are formed in the outside region with average orbital angular momentum remaining unchanged.

[Role of TNF-α in vascular remodeling in rats with chronic thromboembolic pulmonary hypertension]

Objective: To analyze the relationship between TNF-α and pulmonary vascular remodeling in order to explore the pathogenesis of CTEPH. Methods: Autologous blood clots were repeatedly injected into the left jugular vein of rats to establish the CTEPH model. Then mean pulmonary artery pressure (mPAP), histopathology, the plasma level of TNF-α, and the expressions of mRNA and protein of TNF-α in pulmonary artery were measured. Results: In the experiment group, the mPAP and vessel wall area/total area (WA/TA) ratio gradually increased as emblism extended, and increased significantly compared with the sham operation group. The plasma TNF-α concentration in the experimental group increased significantly (P<0.05). The TNF-α proteins expressed in pulmonary artery in the 1-week, 2-week, and 4-week subgroups of experimental group increased significantly compared with the sham operation group (1.62±0.08 vs 0.85±0.12, P<0.05; 1.85±0.08 vs 0.89±0.13, P<0.05; 1.37±0.12 vs 0.91±0.15, P<0.05, respectively). Immunohistochemical results showed that TNF-α expression was higher in pulmonary artery endothelial cells of the experimental group compared with the sham operation group. The expression of pulmonary artery TNF-α protein was positively related with mPAP (r=0.605, P<0.01), and with WA/TA (r=0.629, P<0.01). The expression of serum TNF-α was positively related with that of pulmonary artery TNF-α protein (r=0.721, P<0.01). Conclusion: A rat model of CTEPH can be established by repeatedly introducing autologous blood clots into the pulmonary artery with injecting TXA. Thrombosis induced higher expression of TNF-α in pulmonary arterial endothelial cells, and released into the blood. TNF-α may play an important role in the development of CTEPH, especially by contributing to vascular remodeling and PH.

Characterization and generation of high-power multi-axis vortex beams by using off-axis pumped degenerate cavities with external astigmatic mode converter

The generalized geometric mode with several high-order Hermite-Gaussian (HG) beams localized on ray periodic orbits in the degenerate resonator is generated by an off-axis pumped Nd:YVO₄ laser, by performing beam transformation via an astigmatic mode converter, the generalized geometric modes are found that can be converted into the multi-axis vortex beams with the bundled-rings structures. Experimental results reveal that the generated multi-axis vortex beams can preserve quite stable beam structures even under high-power operation. Moreover, the radius of the bundled rings for the multi-axis vortex beams can be flexibly adjusted by the off-axis pumping to lead to vortex structures with easily controlled orbital angular momentum distribution. The good agreement between the experimental and theoretical results of propagation evolution for the astigmatic transformation of generalized geometric modes further verify the feasibility of using the proposed system to realize various high-powered, multi-center vortex beams with good reliability and predictability.

[Verification of skin paste electrodes used in wireless polysomnography]

OBJECTIVE

To explore an electrode suitable for wireless portable sleep monitoring equipment and analyze the result of the signals of electrooculogram (EOG) and electroencephalography (EEG) collected by this kind of flexible electrodes.

METHODS

The flexible electrodes were prepared by microelectromechanical systems (MEMS) technology. This kind of electrodes consisted parylene, chromium, and gold. Parylene, the flexible substrate of this kind of flexible electrodes, was of biocompatibility. Between parylene and gold there was an adhesion layer of chromium, which connected parylene and gold tightly. Then the flexible electrodes were stuck to medical adhesive tape. The electrodes were designed and made into a grid to make sure that the medical adhesive tape could tape on the skin tightly, so that the contact impedance between the electrodes and the skin would be reduced. Then the alternating current impedance of the electrode were tested by the CHI660E electrochemical workstation after the electrode was achieved. To make sure that this kind of electrodes could be used in EOG monitoring, the electrodes were connected to a wireless signal acquisition suite containing special biological signal acquisition and digital processing chip to gather different sites around the eyes and the electrical signals of different directions of the eye movements, then analyzed the signal-to-noise ratio of the EOG. At the end, the Philips A6 polysomnography was used to compare the noise amplitude of the EEG signals collected by the flexible electrode and the gold cup electrode.

RESULTS

The electrodes stuck to the skin tightly, and these electrodes could collect signals that we wanted while the experiment was performed. The alternating current impedance of the flexible electrode was between 4 kΩ and 13 kΩ while with the frequency of alternating current under 100 Hz, most EEG signal frequencies were at this range. The EOG signals collected by the flexible electrodes were in line with the clinical requirements. The noise amplitude of EEG signals collected by the flexible electrodes was lower than that of the electrical signals collected by the gold cup electrodes.

CONCLUSION

The flexible electrode could be taken into consideration as an alternative electrode for monitoring EOG and EEG signals, and the wireless portable sleep monitoring devices are to be further developed in the future.

Clinical and misdiagnosed analysis of primary pulmonary lymphoma: a retrospective study

Background

The primary pulmonary lymphoma (PPL), with a low incidence, was highly misdiagnosed in clinic. The present study analyzes the clinical features, laboratory and imaging data, pathologic characteristics, and summarizes misdiagnosis reasons of PPL cases, aims to provide a better understanding and increase the accuracy of early diagnosis and minimize the misdiagnosis of PPL.

Methods

The clinical data of 19 cases were collected from the first affiliated hospital of Wenzhou medical university (PRC) from April 2010 to May 2016. All cases were confirmed by pathology. The process of misdiagnosis was described. This study retrospectively analyzed the incidence, clinical presentation, laboratory examination, Chest CT scan and diagnosis of the cases.

Results

The symptoms of the 19 cases were dyspnea, fever, hemoptysis, chest pain or physical findings without obvious symptoms. Five patients were pneumonia-like, nine patients had lung single nodule or mass and four patients got pleural effusion, which were reported by computed tomography (HRCT) scan. There were 2 cases of Hodgkin lymphoma (HL), and 17 cases of non-Hodgkin lymphoma (NHL). In NHL cases, 12 cases were confirmed mucosa associated lymphoid tissue B lymphoma type, 3 cases were confirmed diffuse large B-cell lymphoma, angioimmunoblastic T-cell lymphoma and ALK positive anaplastic large cell lymphoma were one case separately. Clinical and imaging manifestation of PPL is untypical, but there are still some hints: 1) Fuzzy shadow at the edge of lung mass with air bronchogram; 2) Lung mass shadow stable for a long time; 3) Pneumonia-like changing without infections clinical and lab manifestation. Thirteen patients (68.4%) were misdiagnosed as pneumonia, lung cancer and tuberculosis initially. The term between initial diagnosis and final diagnosis lasted for half a month up to 2 years, with median time of 6 months. Two cases were misdiagnosed as tuberculosis. One case was misdiagnosed as small cell lung cancer.

Conclusion

Clinical and imaging manifestation of PPL is untypical. Biopsies should be taken actively if the imaging findings don’t match the symptoms or the anti-infection treatments to “lung infection” don’t work. Accurate diagnosis requires adequate tissue sampling with appropriate ancillary pathologic studies. If clinical manifestation and the diagnosis don’t match, repeated biopsy should be ordered.

Exploring the self-mode locking and vortex structures of nonplanar elliptical modes in selectively end-pumped Nd:YVO4 lasers: manifestation of large fractional orbital angular momentum

An end-pumped Nd:YVO₄ laser under selective pumping is used to excite lasing modes with transverse patterns performed to exhibit the characteristics of multiple spots arranged on elliptical features near degenerate cavities. The spatial distribution of elliptical lasing modes is clearly revealed to be localized on the nonplanar ray orbits, so-called nonplanar elliptical modes, which possess large fractional orbital angular momentum. Moreover, temporal dynamics for the output emission of nonplanar elliptical modes are verified to obtain self-mode-locked operation. We further numerically manifest not only the influence of radial-asymmetry distributions on the vortex structures of nonplanar elliptical modes, but also the vector field of transverse lasing modes altered with twisting phase structures in the propagation direction.

Broad expansion of optical frequency combs by self-Raman scattering in coupled-cavity self-mode-locked monolithic lasers

Broad expansion of optical frequency comb (OFC) by the self-Raman scattering is numerically analyzed and experimentally accomplished in a coupled-cavity self-mode-locked (SML) monolithic Yb:KGW laser. The gain medium is coated to achieve the monolithic SML operation and a partially reflective mirror is further exploited to form the coupled cavity and to multiply the repetition rate up to 128.9 GHz. With a coupled reflectivity of 95%, it is experimentally found that not only the first-order but also second-order stimulated Raman scattering (SRS) can be efficiently generated. The mode-locked OFC can be consequently expanded to reach approximately 8.4 THz, leading the pulse width to be as narrow as 53 fs. At the pump power of 8.7 W, the total output power for the fundamental and the first- and second-Stokes waves can be maintained at 1.6 W. The present exploration provides a promising way to generate the ultrahigh-repetition-rate broadband OFC via the simultaneous SML and SRS processes.

Extracting trajectory equations of classical periodic orbits from the quantum eigenmodes in two-dimensional integrable billiards

The trajectory equations for classical periodic orbits in the equilateral-triangular and circular billiards are systematically extracted from quantum stationary coherent states. The relationship between the phase factors of quantum stationary coherent states and the initial positions of classical periodic orbits is analytically derived. In addition, the stationary coherent states with noncoprime parametric numbers are shown to correspond to the multiple periodic orbits, which cannot be explicable in the one-particle picture. The stationary coherent states are further verified to be linked to the resonant modes that are generally observed in the experimental wave system excited by a localized and unidirectional source. The excellent agreement between the resonant modes and the stationary coherent states not only manifests the importance of classical features in experimental systems but also paves the way to manipulate the mesoscopic wave functions localized on the periodic orbits for applications.

Characterizing classical periodic orbits from quantum Green's functions in two-dimensional integrable systems: Harmonic oscillators and quantum billiards

A general method is developed to characterize the family of classical periodic orbits from the quantum Green's function for the two-dimensional (2D) integrable systems. A decomposing formula related to the beta function is derived to link the quantum Green's function with the individual classical periodic orbits. The practicality of the developed formula is demonstrated by numerically analyzing the 2D commensurate harmonic oscillators and integrable quantum billiards. Numerical analyses reveal that the emergence of the classical features in quantum Green's functions principally comes from the superposition of the degenerate states for 2D harmonic oscillators. On the other hand, the damping factor in quantum Green's functions plays a critical role to display the classical features in mesoscopic regime for integrable quantum billiards, where the physical function of the damping factor is to lead to the coherent superposition of the nearly degenerate eigenstates.

[Clinical evaluation of the revised International Prognostic Score of Thrombosis for essential thrombocythemia (IPSET-thrombosis) in a cohort of 746 Chinese adult patients]

Objective: To evaluate the role of the revised International Prognostic Score of Thrombosis (IPSET-thrombosis) in predicting the occurrence of thrombotic events in Chinese patients with essential thrombocythemia (ET) and to develop a thrombosis predicting model more applicable to Chinese ET patients. Methods: Medical records of 746 adult patients with an initial diagnosis of ET were retrospectively analyzed. Results: The median age at diagnosis was 52 (18-87) years, with 305 males and 441 females. According to the revised IPSET-thrombosis model, the number of very low-, low-, intermediate-, and high-risk patients were 271 (36.3%) , 223 (29.9%) , 63 (8.4%) and 189 (25.3%) , respectively. The four groups exhibited significantly different thrombosis-free survival (χ(2)=72.301, P<0.001) . Thirty-six patients were reclassified as intermediate-risk according to the revised IPSET-thrombosis instead of low-risk as per the original IPSET-thrombosis. Nineteen intermediate-risk patients as per the original IPSET-thrombosis were upgraded to high-risk according to the revised IPSET-thrombosis. Fifty-one high-risk patients as per the original IPSET-thrombosis were reclassified as low-risk in the revised IPSET-thrombosis. It suggests that the revised IPSET-thrombosis potentially avoids over- or under-treatment. In low-risk patients as per the revised IPSET-thrombosis, the rate of thrombosis in patients with cardiovascular risk factors (CVF) was higher than that in those without (16.3% vs 5.2%, χ(2)=5.264, P=0.022) , and comparable with intermediate-risk patients as per the revised IPSET-thrombosis (16.3% vs 14.3%, χ(2)=0.089, P=0.765) . As a result, a new revised IPSET-thrombosis model more applicable to Chinese ET patients was developed in which patients with CVF in the low-risk group as per the revised IPSET-thrombosis were reclassified as intermediate-risk group. Conclusion: For predicting the occurrence of thrombotic events, the revised IPSET-thrombosis model was better than the original IPSET-thrombosis model. The revised IPSET-thrombosis was optimized and a new revised IPSET-thrombosis model more applicable to Chinese ET patients was developed, and the new evidence for risk stratification and treatment of ET in Chinese was provided.

Modelling end-pumped passively Q-switched Nd-doped crystal lasers: manifestation by a Nd:YVO4/Cr4+:YAG system with a concave-convex resonator

A theoretical model for the passively Q-switched (PQS) operation which includes the spatial overlapping between the pump and lasing modes under the thermal lensing effect is developed to give a transcendental equation that can directly determine the critical parameters such as pulse energy, pulse repetition rate, and pulse width for the PQS performance. More importantly, an analytical function which gives the approximate solution for the transcendental equation as well as a specific critical criterion for good PQS operation are derived for practical analyses and design. A Nd:YVO₄/Cr⁴⁺:YAG system with a concave-convex resonator which can achieve fairly stable PQS pulse trains even at a high pump level is further exploited to manifest the proposed spatially dependent model. The good agreement between the experimental results and the theoretical predictions is verified to show the feasibility of the proposed model for designing high-power PQS lasers with high accuracy.

Generation of terahertz optical beating from a simultaneously self-mode-locked Nd:YAG laser at 1064 and 1123 nm

The reflectivity of the output coupler is designed to achieve the synchronously self-mode-locked operation at 1064 and 1123 nm in a diode-end-pumped Nd:YAG laser. Numerical analyses are performed to confirm that the designed output coupler can lead the emission lines to be predominant at 1064 and 1123 nm. Moreover, the crossover of the threshold pump powers for the 1064 and 1123 nm emission lines can be exploited to obtain the single central wavelength of 1064 nm or the single central wavelength of 1123 nm or, simultaneously, dual-central-wavelength self-mode-locked operation by finely adjusting the cavity alignment. For the dual-central-wavelength mode-locked emissions, the pulse repetition rate and the pulse duration are 4.5 GHz and 50.8 ps, respectively. The maximum output power can be up to 2.47 W at a pump power of 7.5 W. The synchronization of the 1064 and 1123 nm mode-locked pulses generates the optical beating pulse trains with repetition rates up to 14.7 THz.

Energy content and amino acid digestibility of flaxseed expellers fed to growing pigs

This study was conducted to determine the DE and ME as well as the apparent ileal digestibility (AID) and standardized ileal digestibility (SID) of CP and AA in flaxseed expellers fed to growing pigs. In Exp. 1, the DE and ME were determined using 66 crossbred growing pigs (Duroc × Landrace × Yorkshire; 54.2 ± 2.3 kg BW) fed 1 of 11 diets in a completely randomized design. The diets included a corn-soybean meal basal diet and 10 experimental diets containing 29.16% flaxseed expellers supplemented at the expense of corn and soybean meal. In Exp. 2, 11 growing pigs (35.5 ± 3.4 kg), fitted with a T-cannula at the distal ileum, were assigned to 6 × 11 Youden square design with 6 periods and 11 diets. The diets included a N-free diet based on cornstarch and sucrose and 10 test diets containing 40% flaxseed expellers as the sole source of AA. Chromic oxide (0.3%) was used as an indigestible marker. There was considerable variation in the chemical composition among the 10 flaxseed expellers. The CV were greater than 10% for ether extract (EE), NDF, ADF, crude fiber, and Ca and ranged from 7 to 12% for the AA. On a DM basis, the DE and ME ranged from 2,786 to 3,730 and from 2,588 to 3,530 kcal/kg, respectively. The apparent total tract digestibility of GE ranged from 59.91 to 75.83% (mean = 70.92%). Ether extract, GE, and NDF were the best predictors to determine DE and ME. The best prediction equations were DE = -3,231 + (1.58 × GE) - (25.79 × % NDF) ( = 0.90) or DE = 4,189 + (56.78 × % EE) - (30.59 × % NDF) ( = 0.85) and ME = -2,968 + (1.47 × GE) - (24.82 × % NDF) ( = 0.85) or ME = 3,931 + (53.77 × % EE) - (29.31 × % NDF) ( = 0.82), respectively. In Exp. 2, there were significant differences in the AID and SID of CP and all AA with the exception of Phe ( < 0.05). The AID and SID of CP averaged 70.16 and 78.04%, respectively. For the indispensable AA, the AID and SID of Thr were the least, with average values of 70.70 and 76.68%, respectively. The digestibility of Arg and Met were the greatest, averaging over 88 and 91% for AID and SID, respectively. The AID and SID of Lys ranged from 66.10 to 81.82% (mean = 74.14%) and from 70.90 to 85.41% (mean = 78.13%), respectively. These results indicate that there is significant variability in chemical composition, energy content, and the SID and AID of CP and AA among the selected flaxseed expellers. The DE and ME of flaxseed expellers are primarily related to their EE and NDF concentrations.

Exploiting concave-convex linear resonators to design end-pumped solid-state lasers with flexible cavity lengths: Application for exploring the self-mode-locked operation

The characteristics of a convex-concave linear resonator under the thermal lensing effect are theoretically analyzed to find an analytical model for designing end-pumped solid-state lasers with flexible cavity lengths. By exploiting the design model, the power scaling for continuous-wave operation under strong thermal lensing can be easily achieved in the proposed resonator with different cavity lengths. Furthermore, the proposed resonator is applied to explore the exclusive influence of cavity length on the self-mode-locked (SML) operation. It is discovered that the lasing longitudinal modes will split into multiple groups in optical spectrum to lead to a multi-pulse mode-locked temporal state when the cavity length increases. Finally, a theoretical model is derived to reconstruct the experimental results of SML operation to deduce a simple relationship between the group number of lasing modes and the cavity length.

Monolithic dual-polarization self-mode-locked Nd:YAG 946-nm lasers: controlling beat frequency and observation of temporal chaos

The self-mode-locked (SML) operation at 946 nm can be achieved with a monolithic Nd:YAG crystal when the pump power is above the threshold of the multiple-longitudinal-mode generation. The SML output is further found to include two orthogonal polarization components with a beat frequency coming from the birefringence effect in the laser crystal. The beat frequency can be widely adjusted in the range of 5-220 MHz by controlling the cooling temperature. The present experiment also confirms the theoretical prediction that the two-mode operation generally exhibits the chaotic dynamics when the frequency difference is sufficiently close to the relaxation frequency.

Exploring vortex structures in orbital-angular-momentum beams generated from planar geometric modes with a mode converter

It is theoretically demonstrated that the planar geometric mode with a π/2 mode converter, so called the circularly geometric mode, can be solved from the inhomogeneous Helmholtz equation by considering the pump distribution on the lasing mode. Theoretical analysis clearly reveal that the vortex structures of circularly geometric modes are determined by the minimum order of transverse lasing modes, the total number of transverse lasing modes and the degenerate condition in the cavity. Moreover, we experimentally manifest that the circularly geometric mode can be generated from the selective pumped solid-state laser with an external π/2 mode converter. To explore the vortex structures of the generated geometric modes, the interference patterns are performed by an experimental apparatus consisting of a Mach-Zehnder interferometer. The good agreement between experimental observations and numerical calculations confirms the analysis of vortex structures is reliable.

Synchronized self-mode-locked 1061-nm and 1064-nm monolithic Nd:YAG laser at cryogenic temperatures with two orthogonally polarized emissions: generation of 670 GHz beating

A dual-wavelength self-mode-locked monolithic Nd:YAG laser at 1061 and 1064 nm is realized at cryogenic temperatures. At an incident pump power of 5.5 W, the total output power can reach 2.5 W and the mode-locked pulse width is 29 ps at a pulse repetition rate of 7.75 GHz. The synchronization of the dual-wavelength emissions leads to a beat frequency of 670 GHz in the individual mode-locked pulse. It is further discovered that the laser output consists of two orthogonally polarized components with a central frequency difference of 127 MHz. The central frequency difference between two orthogonal polarizations mainly arises from the external mechanical stress introduced by the copper holder for the laser crystal.

[The effect of locally injected betamethasone on collagen deposition in benign central airway stenosis]

OBJECTIVE

To assess the effects of locally injected betamethasone on cicatricial tissue hyperplasia in patients with benign central airway stenosis.

METHODS

A prospective study was conducted with 2 treatment modalities: conventional interventional(CI)therapy, and CI combined with local betamethasone injection(LBI). The average optical density value of TGF-β1 and collagen density in the local airway tissues were compared before therapy and 7 d after the CI treatment and the LBI treatment, respectively.

RESULTS

Six patients were recruited in this study from May 2013 to June 2015.The results showed significant statistical differences by paired t-test in TGF-β1: 92±38 vs 164±47(t=-7.984, P=0.000)before and after the CI treatment, respectively; 128±45 vs 78±40 (t=10.055, P=0.000)before and after the LBI treatment, respectively. The collagen density was 91 932±59 520 vs 150 252±76 673(t=-8.105, P=0.000) before and after the CI treatment, respectively; 107 024±54 880 vs 114 038±50 772(t=-0.621, P=0.54) before and after the LBI treatment, respectively.Trend comparisons made before and after the treatments showed significant statistical differences in TGF-β1(F=712.139, P=0.000) and in the collagen density (F=261.256, P=0.000)between the CI treatment and the LBI treatment groups.

CONCLUSIONS

The CI treatment was shown to stimulate the production of TGF-β1 and the deposition of collagen, while the LBI treatment was shown to reduce the production of TGF-β1 and alleviate the deposition of collagen from the stimulation of the CI treatment.

Observation of reflection feedback induced the formation of bright-dark pulse pairs in an optically pumped semiconductor laser

It is experimentally demonstrated that the tiny reflection feedback can lead the optically pumped semiconductor laser (OPSL) to be operated in a self-mod-locked state with a pulse train of bright-dark pulse pairs. A theoretical model based on the multiple reflections in a phase-locked multi-longitudinal-mode laser is developed to confirm the formation of bright-dark pulse pairs. The present finding can offer an important insight into the temporal dynamics in mode-locked OPSLs.

Protective Effects of Chaihu Shugan San () on Nonalcoholic Fatty Liver Disease in Rats with Insulin Resistance

OBJECTIVE

To investigate the protective effects of Chinese medicine formulation Chaihu Shugan San (, CHSGS) on nonalcoholic fatty liver disease (NAFLD) in rats with insulin resistance (IR) and its molecular mechanisms.

METHODS

Male Sprague-Dawley rats were randomly divided into six groups: the control group, the model group, Dongbao Gantai group (, DBGT, 0.09 g methionine/kg), CHSGS high-dose group (CHSG-H, 12.6 g crude drug/kg), CHSGS medium-dose group (CHSG-M, 6.3 g crude drug/kg), and CHSGS low-dose group (CHSG-L, 3.15 g crude drug/kg). After establishing the NAFLD rat model and treatment for 8 weeks, total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), free fatty acid (FFA), fasting blood glucose (FBG), fasting insulin (FINS) contents in blood serum, and TC, TG contents in the hepatic homogenate were measured by an automatic biochemical analyzer, and a homeostasis model assessment was applied to assess the status of IR, insulin sensitivity index (ISI), and homeostasis model assessment for insulin secretion (HOMA-IS). The expression levels of adiponectin and leptin mRNA in liver tissue were analyzed by reverse transcription polymerase chain reaction. Pathological changes of livers were observed by hematoxylin-eosin staining of paraffin section.

RESULTS

Compared with the model group, the serum levels of TC, TG, FFA, FBG, FINS, IRI, ISI, and the liver levels of TC and TG in CHSG-H, CHSG-M, CHSG-L groups showed significant declines (P<0.01 or P<0.05); the serum levels of HDL-C, HOMA-IS were significantly increased (P<0.01 or P<0.05); the expression of leptin mRNA was dramatically decreased and the expression of adiponectin mRNA was increased in the hepatic tissue (P<0.01 or P<0.05). The fatty deposition of liver cells could also be alleviated.

CONCLUSION

CHSGS could up-regulate the expression of adiponectin mRNA and down-regulate the expression of leptin mRNA on the liver, suggesting the CHSGS had positive therapeutic effect on NAFLD in rats with IR.

Exploring transverse pattern formation in a dual-polarization self-mode-locked monolithic Yb: KGW laser and generating a 25-GHz sub-picosecond vortex beam via gain competition

Formation of transverse modes in a dual-polarization self-mode-locked monolithic Yb: KGW laser under high-power pumping is thoroughly explored. It is experimentally observed that the polarization-resolved transverse patterns are considerably affected by the pump location in the transverse plane of the gain medium. In contrast, the longitudinal self-mode-locking is nearly undisturbed by the pump position, even under the high-power pumping. Under central pumping, a vortex beam of the Laguerre-Gaussian LGp,l mode with p = 1 and l = 1 can be efficiently generated through the process of the gain competition with a sub-picosecond pulse train at 25.3 GHz and the output power can be up to 1.45 W at a pump power of 10.0 W. Under off-center pumping, the symmetry breaking causes the transverse patterns to be dominated by the high-order Hermite-Gaussian modes. Numerical analyses are further performed to manifest the symmetry breaking induced by the off-center pumping.

Generation of orthogonally polarized self-mode-locked Nd:YAG lasers with tunable beat frequencies from the thermally induced birefringence

The simultaneous self-mode-locking of two orthogonally polarized states in a Nd:YAG laser is demonstrated by using a short linear cavity. A total output power of 3.8 W can be obtained at an incident pump power of 8.2 W. The beat frequency Δfc between two orthogonally polarized mode-locked components is observed and measured precisely. It is found that the beat frequency increases linearly with an increase in the absorbed pump power. The origin of the beat frequency can be utterly manifested by considering the thermally induced birefringence in the Nd:YAG crystal. The present result offers a promising approach to generate orthogonally polarized mode-locked lasers with tunable beat frequency.

Theoretical and experimental studies for high-repetition-rate disordered crystal lasers with harmonic self-mode locking

A harmonically self-mode-locked Nd:Sr3Y2/(BO3)4 disordered crystal laser with subpicosecond pulse duration is demonstrated. We exploit the damped harmonic oscillator model to numerically verify that the mode spacing of the laser cavity can be modified to be the harmonics of the free spectral range of the Fabry-Perot cavity when the optical length of the laser cavity is close to a commensurate ratio of the optical length of the Fabry-Perot cavity. In experiment, the Fabry-Perot cavity can be formed by the pump facet of the disordered crystal and the front mirror. A 110 GHz single-pulse harmonically mode-locked pulse train with pulse duration of 857 fs is experimentally achieved under optical lengths of 27.19 and 4.08 mm for the laser cavity and Fabry-Perot cavity respectively, corresponding to a fractional number of 20/3. A maximum output power of 162 mW is obtained at an incident pump power of 3.1 W.

Effect of obstructive sleep apnoea on diabetic retinopathy and maculopathy: a systematic review and meta-analysis

AIMS

To summarize the association between obstructive sleep apnoea and diabetic retinopathy and diabetic maculopathy, and to examine the effects of oxygen desaturation index, mean and minimum oxygen saturation and time spent with < 90% oxygen saturation on diabetic retinopathy and diabetic maculopathy.

METHODS

A systematic search was performed for papers published from inception to January 2014 in MEDLINE, EMBASE and the Cochrane Database of Systematic Reviews using indexed terms and free text. Additional searches were carried out for grey literature. Two authors conducted the study selection and quality assessment. Data extraction was performed by the main author and checked by the other authors.

RESULTS

One cohort study and 15 cross-sectional studies were included for narrative synthesis and three for meta-analyses. There was no convincing evidence that obstructive sleep apnoea was associated with diabetic retinopathy, although some evidence suggested that obstructive sleep apnoea was associated with greater severity of diabetic retinopathy and advanced diabetic retinopathy in people with Type 2 diabetes. Only six studies examined the impact of obstructive sleep apnoea on diabetic maculopathy and our narrative review suggests there is an association in Type 2 diabetes. Oxygen desaturation index, mean oxygen saturation or time spent with < 90% oxygen saturation were not associated with diabetic retinopathy, and insufficient evidence was available to draw conclusions on their effects on diabetic maculopathy; however, there was evidence from both narrative synthesis and meta-analysis that minimum oxygen saturation had an impact on diabetic retinopathy (pooled odds ratio 0.91, 95% CI 0.87-0.95; I(2) = 0%).

CONCLUSIONS

There is a need for large cohort studies with long-term follow-up data to examine the long-term effects of obstructive sleep apnoea and other sleep variables on advanced retinal disease in diabetes.