Identification of diagnostic biomarkers and immuno-infiltration analysis for rheumatoid arthritis based on biological information and WGCNA.

OBJECTIVE: Rheumatoid arthritis (RA), as an autoimmune disease, poses a huge social and economic burden worldwide. Although the diagnosis of RA has been gradually improved, there is still a need to discover accurate and rapid biomarkers for diagnosis and therapy with a precise understanding of the disease. This study aimed to screen diagnostic biomarkers and analyze immune infiltration in RA based on weighted gene co-expression network analysis (WGCNA). MATERIALS AND METHODS: Firstly, we screened the experimental and validation sets associated with RA from the GEO database. Crossover genes were obtained using differential genes (DEGs) and key modules in WGCNA. Subsequently, the crossover genes were constructed into protein-protein interaction (PPI) networks and screened to obtain hub genes. The receiver operating characteristic (ROC) curve assessment was performed to identify diagnostic biomarkers. In addition, we used the Cibersort algorithm for immuno-infiltration analysis and the DGidb database to search for drugs associated with diagnostic biomarkers. RESULTS: In the end, 377 DEGs were identified, and the enrichment analysis revealed significant associations with the immune system. Blue modules in the WGCNA analysis were positively associated with the disease and were identified as key modules. ROC curves evaluated the four hub genes, which significantly differentiated RA from healthy controls and could be used as diagnostic biomarkers. In further analysis, we found that RA is closely related to immunity, and the search identified multiple drugs that hold promise for treating RA. CONCLUSIONS: BCL2A1, PTGS2, FAS, and LY96 may be used as diagnostic biomarkers, which is significant for diagnosing and treating RA.

[Association between platelet parameters and risk for stroke in people with different blood pressure levels: Dongfeng-Tongji cohort].

Objective: To explore the associations of platelet parameters platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW) and plateletcrit (PCT) with the risk for stroke in people with different blood pressure levels. Methods: All the participants were from Dongfeng-Tongji cohort, including 38 295 retired employees from Dongfeng Motor Corporation at the first follow-up survey. After excluding participants with coronary heart disease, stroke, cancer, history of platelet influential drug use and those with missed data of platelet parameters or blood pressure or lost to follow-up, finally a total of 21 294 participants were included in this study. All the participants completed baseline questionnaires, physical examinations, clinical biochemical tests, and blood sample collection. Cox proportional hazard models were used to estimate the hazard ratios (HRs) and the corresponding 95% confident intervals (CIs) for the associations between platelet parameters and risk for stroke in people with different blood pressure levels. Results: After a mean follow-up of 8.0 years, 1 578 participants developed incident stroke [1 266 ischemic stroke (IS) cases and 312 hemorrhagic stroke (HS) cases]. Compared with the participants with PLT<188×109/L, those with PLT≥188×109/L among hypertension cases were significantly associated with higher risks for stroke and IS (stroke: HR=1.27, 95%CI: 1.12-1.44; IS: HR=1.39, 95%CI: 1.21-1.60). Among hypertension group, compared with participants with PCT<0.165%, PCT≥0.165% were significantly associated with higher risk for stroke (HR=1.15, 95%CI: 1.01-1.30) and lower risk for HS (HR=0.70, 95%CI: 0.53-0.93); Among non-hypertension and hypertension group, PCT ≥0.165% were significantly associated with higher risks of IS (HR=1.27, 95%CI: 1.05-1.54; HR=1.31, 95%CI: 1.14-1.50). MPV and PDW were not significantly associated with risk for stroke. Risk for stroke increased significantly in hypertension cases with different platelet parameters levels compared with non-hypertension cases with lower levels of each platelet parameters. Conclusion: Higher levels of PLT and PCT could increase the risks for stroke and IS in middle-aged and elderly hypertension patients, and lower levels of PCT could decrease the risk for HS in hypertension patients.

Identification of Vibrio alginolyticus virulent strain-specific DNA regions by suppression subtractive hybridization and PCR.

AIMS: Vibrio alginolyticus was frequently isolated from diseased farmed fish in the coaster waters of Hainan Island over the past two decades. In this study, we attempted to identify candidates of virulent strain-specific DNA regions for this pathogen. METHODS AND RESULTS: Suppression subtractive hybridization (SSH) and PCR were successively performed between the typical virulent strain and avirulent strain of V. alginolyticus, in which they shared 99·54% homology of 16S rDNAs. Out of 2873 subtracted clones, nine clones were finally indicated to harbour virulent strain-specific DNA fragments. The receivable functions of the major fragments in the nine clones were believed to encode methyl-accepting chemotaxis protein (n = 1), type VI secretion system-associated FHA domain protein TagH (n = 1), diguanylate cyclase (n = 1), AraC family transcriptional regulator (n = 1), ABC-type uncharacterized transport system permease component (n = 1) and hypothetical proteins (n = 4). Two hypothetical proteins contain several disordered regions. CONCLUSIONS: Some specific DNA regions existed in the virulent strain of V. alginolyticus, and the SSH assay could be a highly sensitive method for identifying virulent regions in pathogens. SIGNIFICANCE AND IMPACT OF THE STUDY: This report is the first to describe the identification of virulent strain-specific DNA regions in the V. alginolyticus genome, which is helpful in developing virulent strain-specific rapid detection methods and is a pivotal precondition for clarifying the molecular virulence mechanism of V. alginolyticus.

[Surgical treatment of port-site metastases after laparoscopic radical resection of gastric cancer].

Objective: To investigate the feasibility of surgical treatment of port-site metastasis after laparoscopic radical resection of gastric cancer. Methods: The clinical and follow-up data of five patients with port-site metastases after laparoscopic radical resection of gastric cancer at Zhejiang Provincial People's Hospital between January 2014 and January 2018 were retrospectively analyzed. Results: Port-site metastases occurred within 6 months after gastrointestinal tumor resection in three patients, 10 months after the operation in one patient, and 30 months after the operation in one patient, respectively. Metastasis to the abdominal cavity or distant metastasis was excluded before the surgical treatment of the port-site metastases, and all patients recovered well after the operation. No incisional infection or hernia occurred. By December 2018, two patients died (they survived for 13 and 24 months, respectively) and three patients survived. The follow-up duration ranged from 7 to 19 months. Conclusions: Surgical resection of port-site metastases is not difficult due to their superficial location. Surgical treatment can improve the prognosis of patients without abdominal or distant metastasis/recurrence.

[Cytomegalovirus active infection after kidney transplantation affecting the expression of activation receptor CD226 on NKT cell].

Objective: To investigate the effect of active cytomegalovirus infection post kidney transplant on the expressing of receptor CD226 on NKT cell. Methods: Case controlled study. From December 2013 to December 2014, 43 cases of kidney transplant recipient with CMV infection were collected in the Organ Transplantation Research Institute of the former 309th Hospital of PLA. The healthy control group included 15 cases. 15 cases of recipients who were stable after operation and followed up in our hospital at the same time were also collected as control. Peripheral blood specimen with EDTA as anticoagulant were used and analyzed by flow cytometry. Results: The population of NKT in CMV infection recipients were 5.19(1.18, 25.92)%, while in the remission stage the population were 4.89(0.68, 25.33)%, Compared with normal healthy controls and the stable recipients, the percentage of CD3(+)CD56(+) NKT cells in periphery blood mononuclear cells did not vary among these groups(P>0.05). The CD226(+) NKT population during the active CMV infection was (70±13)%, which was significantly lower than the health control [(87±10)%] and stable recipients [(80±9)%](P<0.001). Whereas in the CMV infection remission stage, the CD226(+)NKT population was (81±16)%, which was significantly higher than that of CMV active infection group (P<0.05), and showed no difference with the health control group and stable recipients (P>0.05). The CD226 MFI expressed on NKT in CMV infection group was 101±49, which showed no difference with health controls and stable recipients (P>0.05). However, significantly up regulation of CD226 MFI on NKT was observed in the samples obtained from the same recipients in CMV active infection (91±40) and in CMV regression stage(173±73)(P<0.001). Conclusions: The CD226(+) NKT cells population was down during the active CMV infection post kidney transplantation, while the expression of CD226 and the population of CD226(+)NKT could regression when the CMV infection regressed, which indicates the involvement of CD226 in the process of NKT cells anti-CMV infection.

IGFBP2 promotes vasculogenic mimicry formation via regulating CD144 and MMP2 expression in glioma.

Vasculogenic mimicry (VM) refers to the fluid-conducting channels formed by aggressive tumor cells rather than endothelial cells (EC) with elevated expression of genes associated with vascularization. VM has been considered as one of the reasons that glioblastoma becomes resistant to anti-VEGF therapy. However, the molecular basis underlying VM formation remains unclear. Here we report that the insulin-like growth factor-binding protein 2 (IGFBP2) acts as a potent factor to enhance VM formation in glioma. Evidence showed that elevated IGFBP2 expression was positively related with VM formation in patients with glioma. Enforced expression of IGFBP2 increased network formation of glioma cells in vitro by activating CD144 and MMP2 (Matrix Metalloproteinase 2). U251 cells with stable knockdown of IGFBP2 led to decreased VM formation and tumor progression in orthotopic mouse model. Mechanistically, IGFBP2 interacts with integrin α5 and ß1 subunits and augments CD144 expression in a FAK/ERK pathway-dependent manner. Luciferase reporter and ChIP assay suggested that IGFBP2 activated the transcription factor SP1, which could bind to CD144 promoter. Thus, IGFBP2 acts as a stimulator of VM formation in glioma cells via enhancing CD144 and MMP2 expression.

Growth and laser properties of Nd3+-doped Bi4Ge3O12 single-crystal fiber.

The Nd3+-doped Bi4Ge3O12 (BGO) single-crystal fiber (SCF) was successfully grown by the micro-pulling-down method with the resistance heating system. The fluorescence spectrum and transmission spectrum of the Nd:BGO SCF were measured. Excited by a continuous-wave 808-nm laser diode, a fluorescence peak around 1064 nm was observed. At an absorbed pump power of 15.25 W, the Nd:BGO SCF laser delivered a power of 3.37 W with a slope efficiency of 31.2%.

[A review about the research progress of the acoustical-electrical transducer for totally implantable cochlear implant].

Cochlear implantation has become a crucial approach for the treatment for patients with severe and profound sensorineural hearing loss. However, some patients would be embarrassed by the exterior components, which limited the patient's social activities. The idea of totally implantable cochlear implant (TICI) was put forward to alleviate these inconveniences. The implantable acoustical-electrical transducer would be a breakthrough in the study of TICI. In this paper, a summary of all kinds of designs ideas was made.

Characteristics and clinical use of ocular and cervical vestibular evoked myogenic potentials for evaluating paediatric candidates for cochlear implants.

OBJECTIVE: This study aimed to define the characteristics and use of ocular and cervical vestibular evoked myogenic potentials for evaluating paediatric cochlear implant candidates. METHODS: Ocular and cervical vestibular evoked myogenic potentials of 34 paediatric cochlear implant candidates were analysed. All patients also underwent a routine audiological examination, including computed tomography. RESULTS: In all, 27 patients with normal inner-ear structures had absent or impaired vestibular evoked myogenic potential responses. In paediatric candidates with inner-ear malformations, ocular and cervical vestibular evoked myogenic potentials had lower thresholds and higher amplitudes. Vestibular evoked myogenic potential responses in this cohort were classified into three groups. There was significant concordance between vestibular evoked myogenic potentials and temporal bone computed tomography findings. CONCLUSION: Ocular and cervical vestibular evoked myogenic potential waveforms were different in paediatric candidates with normal and abnormal inner-ear structures. Therefore, vestibular evoked myogenic potential responses can indicate temporal bone structure.

Transplantation of RADA16-BDNF peptide scaffold with human umbilical cord mesenchymal stem cells forced with CXCR4 and activated astrocytes for repair of traumatic brain injury.

Due to the poor self-regeneration of brain tissue, stem cell transplantation therapy is purported to enable the replacement of lost neurons after traumatic brain injury (TBI). The main challenge of brain regeneration is whether the transplanted cells can survive and carry out neuronal functions in the lesion area. The brain is a complex neuronal network consisting of various types of cells that significantly influence on each other, and the survival of the implanted stem cells in brain is critically influenced by the surrounding cells. Although stem cell-based therapy is developing rapidly, most previous studies just focus on apply single type of stem cells as cell source. Here, we found that co-culturing human umbilical cord mesenchymal stem cells (hUC-MSCs) directly with the activated astrocytes benefited to the proliferation and neuron differentiation of hUC-MSCs in vitro. In this study, hUC-MSCs and the activated astrocytes were seeded in RADA16-BDNF peptide scaffold (R-B-SPH scaffold), a specifical self-assembling peptide hydrogel, in which the environment promoted the differentiation of typical neuron-like cells with neurites extending in three-dimensional directions. Moreover, the results showed co-culture of hUC-MSCs and activated astrocytes promoted more BDNF secretion which may benefit to both neural differentiation of ectogenic hUC-MSCs and endogenic neurogenesis. In order to promote migration of the transplanted hUC-MSCs to the host brain, the hUC-MSCs were forced with CXC chemokine receptor 4 (CXCR4). We found that the moderate-sized lesion cavity, but not the large cavity caused by TBI was repaired via the transplantation of hUC-MSCsCXCR4 and activated astrocytes embedded in R-B-SPH scaffolds. The functional neural repair for TBI demonstrated in this study is mainly due to the transplantation system of double cells, hUC-MSCs and activated astrocytes. We believe that this novel cell transplantation system offers a promising treatment option for cell replacement therapy for TBI. STATEMENT OF SIGNIFICANCE: In this reach, we specifically linked RGIDKRHWNSQ, a functional peptide derived from BDNF, to the C-terminal of RADARADARADARADA (RADA16) to structure a functional self-assembling peptide hydrogel scaffold, RADA16-BDNF (R-B-SPH scaffold) for the better transplantation of the double cell unit. Also, the novel scaffold was used as cell-carrier for transplantation double cell unit (hUC-MSCs/astrocyte) for treating traumatic brain injury. The results of this study showing that R-B-SPH scaffold was pliancy and flexibility to fit the brain lesion cavity and promotes the outgrowth of axons and dendrites of the neurons derived from hUC-MSCs in vitro and in vivo, indicating the 3D R-B-SPH scaffold provided a suitable microenvironment for hUC-MSC survival, proliferation and differentiation. Also, our results showing the double-cells transplantation system (hUC-MSCs/astrocyte) may be a novel cell-based therapeutic strategy for neuroregeneration after TBI with potential value for clinical application.

TBX21 polymorphisms are associated with virus persistence in hepatitis C virus infection patients from a high-risk Chinese population.

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease and the varied outcomes of the infection depend on both viral and host factors. We have demonstrated that the HCV alternate reading frame protein (F protein) is related to Th1/Th2 bias which is involved in virus persistence in chronic hepatitis C (CHC) patients. The purpose of this study was to test the hypothesis that genetic variants of TBX21 (T cell specific T-box transcription factor) were associated with the outcomes of HCV infection and F protein generation. Three single nucleotide polymorphisms (SNPs) (rs17250932, rs2074190, rs4794067) in the TBX21 gene were genotyped in a case-control study in a cohort of a high-risk group, including 354 healthy controls and 747 CHC patients (190 anti-F protein antibody seronegative patients and 557 anti-F protein antibody seropositive patients). Results showed that the rs4794067 C allele in the TBX21 promoter was significantly more common in CHC patients (OR = 1.335, 95% CI = 1.058-1.684, P = 0.015), exceptionally in anti-F protein seropositive patients (OR = 1.547, 95% CI = 1.140-2.101, P = 0.005), compared with healthy controls. And the risk effect was also significantly high in patients with HCV 1b genotype and mild fibrosis (P = 0.021, P = 0.010, respectively). Compared with the most frequent haplotype TAT, haplotype analysis showed that the distribution of TAC was significantly different between the chronic HCV carrier group and the healthy group, and so was the anti-F antibody seronegativity group and the anti-F antibody seronegativity group (all P < 0.001). Our results suggested that TBX21 variants may be involved in the etiology of this disease.

Dual-wavelength synchronous operation of a mode-locked 2-µm Tm:CaYAlO4 laser.

We experimentally demonstrated dual-wavelength synchronous operation of a high-power passively mode-locked 2-µm Tm:CaYAlO4 (Tm:CYA) disordered crystal laser with semiconductor saturable absorber mirror (SESAM) as mode locker. The mode-locked laser emitted an average output power as high as 830 mW with pulse duration of 35.3 ps and repetition rate of 145.4 MHz. The mode-locking dual wavelengths were centered at 1958.9 nm and 1960.6 nm, respectively. Autocorrelation trace clearly shows beating pulses with pulse width of 3.5 ps and repetition rate of 0.13 THz.

First Report of Greenhouse Tomato Wilt Caused by Plectosphaerella cucumerina in China.

Tomato (Lycopersicon esculentum Mill.) is one of the most important vegetable crops in China. In May 2011, root rot and plant wilt were observed on tomato plants (variety Jinguan No. 5 and Meina) in 26 commercial greenhouses in Huludao city, Liaoning Province, China. Disease incidence was 30 to 95%. At beginning of fruit set, symptoms were chlorosis of lower leaves and lack of turgidity in young leaves. Severely affected plants were wilted and stunted as fruit approached maturity. Primary and secondary roots became necrotic with few fine feeder roots. Symptomatic roots were collected and cut into small pieces, disinfested in 2% sodium hypochlorite for 2 min, rinsed with sterile water, and placed on potato dextrose agar. After incubation at 25°C for 5 days, 20 axenic cultures were obtained from single conidia. Colonies were buff or salmon pink, moist, and had appressed, slimy mycelium. Aerial mycelium was sparse with simple or branched conidiophores. Conidia were 4.0 to 8.9 × 2.0 to 4.0 (average 6.9 × 2.8) µm, aggregated in slimy heads, hyaline ellipsoidal and ovoid, smooth, and 0 to 1 septate. Conidia were borne on phialides that were 6.3 to 24.3 × 1.4 to 3.3 (average 15.9 × 2.2) µm. These characteristics are typical of Plectosphaerella cucumerina (Lindf.) W. Gams (1) (anamorph: Fusarium tabacinum) (3). The internal transcribed spacer (ITS) region of the 20 isolates was amplified using the primers ITS1/ITS4 and sequenced. Identical sequences were obtained from all 20 isolates, and the sequence of isolate HLDT15 was submitted to GenBank (Accession No. KC894931). BLAST analysis of the sequence showed 100% similarity to P. cucumerina (AB469880). Pathogenicity tests were conducted with tomato variety Jinguan No. 5. Six 12-liter pots were filled with sterilized potting mix (equal parts sand, peat, and soil) and 200 ml conidial suspension (1 × 105 conidia ml-1). The conidial suspension of the isolate of P. cucumerina was prepared from 7-day-old cultures grown in potato dextrose broth on a shaker (120 rpm) at 25 ± 1°C. Six control pots were filled with potting mix and 200 ml of sterilized potato dextrose broth. Each pot was sown with six surface-sterilized (2% sodium hypochlorite for 2 min) tomato seeds. All the pots were kept in a greenhouse at 23 to 28°C. Three to four weeks after seedling emergence, all inoculated plants were dwarfed and lower leaves were chlorotic. Roots were necrotic and produced fewer fibrous roots. All characteristics were similar to original observations on the host of origin. Control plants remained asymptomatic. The same results were obtained when pathogenicity tests were repeated twice. P. cucumerina was reisolated from inoculated plants and matched the morphological and molecular characteristics of the original isolates. P. cucumerina was reported as a pathogen of tomato in Italy (2) and Australia (4). To our knowledge, this is the first report of P. cucumerina causing tomato wilt in China. So far, we have observed the disease on tomatoes in commercial greenhouses of Pulandian and Panjin city, Liaoning Province, China. The spread of this disease may pose a threat to tomato production in China. References: (1) A. Carlucci et al. Persoonia 28:34, 2012. (2) A. Matta et al. Riv. Patol. Veg. 14:119, 1978. (3) M. E. Palm et al. Mycologia, 87:397, 1995. (4) I. G. Pascoe et al. Mycol. Soc. 83:343, 1984.

Effect of microbiological and immunological enteral nutrition on intestinal function and immune status in the patients with long-term use of antibiotics.

BACKGROUND: To investigate the effect of microbiological and immunological enteral nutrition (MEIN composed by probiotics, L-Glutamide, deep-sea fish oil and Nutrison Fibre) on intestinal function and immune status in the patients with long-term use of antibiotics. PATIENTS AND METHODS: 56 severe apoplexy patients with pulmonary infectious complication were randomly divided into two groups: a microbiological and immunological enteral nutrition group (MEIN group, n=28) and an enteral nutrition group (EN group, n=28). MEIN suspension (Live Combined Bifidobacterium, L-Glutamide, deep-sea fish oil and Nutrison Fibre) and ordinary enteral nutrition liquid (Nutrison Fibre) were given to patients of the MEIN group and EN group respectively for at least for 20 days. Then the trophonemata, incidence rates of abdominal pain, abdominal distention and diarrhea, tolerance and immunologic parameters including CD4+, CD8+ T-lymphocyte percentage, CD4+/CD8+ ratio and NK cells in peripheral blood were estimated and compared between the two groups during the period of nutritional support. RESULTS: No statistical difference was observed in trophonemata between the two groups (p > 0.05). The abdominal pain and abdominal distension incidence rates of the patients in MEIN group were significantly lower than those of patients in EN group. (7.2% vs 32.1%, 14.2% vs 39.3%, 0% vs 10.7%) (p < 0.05). There was a significantly better tolerance in MEIN group compared to EN group after treatment (p < 0.05). In addition, the levels of immune parameters of the patients in MEIN group were much higher compared to that of those in EN group on the 20th day after grouping (p < 0.05). CONCLUSIONS: Compared with the general formula EN, MEIN is more helpful for the patients with Long-term use of antibiotics in improving intestinal function and cellular immune function.

Diode-pumped continuous wave tunable and graphene Q-switched Tm:LSO lasers.

We have investigated the lasing characteristics of Tm:LSO crystal in three operation regimes: continuous wave (CW), wavelength tunable and passive Q-switching based on graphene. In CW regime, a maximum output power of 0.65 W at 2054.9 nm with a slope efficiency of 21% was achieved. With a quartz plate, a broad wavelength tunable range of 145 nm was obtained, corresponding to a FWHM of 100 nm. By using a graphene saturable absorber mirror, the passively Q-switched Tm:LSO laser produced pulses with duration of 7.8 µs at 2030.8 nm under a repetition rate of 7.6 kHz, corresponding to pulse energy of 14.0 µJ.

First Report of Gray Leaf Spot of Maize Caused by Cercospora zeina in China.

Gray leaf spot of maize (Zea mays L.) is an important foliar disease in many parts of China. The causal organism of gray leaf spot in China is generally regarded as Cercospora zeae-maydis (3). In October 2011, symptoms similar to gray leaf spot were observed on 77% of maize plants in 25 locations (about 3,000 ha.) of Yunnan Province, China, and the disease could cause yield losses of 35 to 50%. The symptoms of leaf spot were different from those caused by C. zeae-maydis. The lesions on leaves were oblong, pale gray to pale brown, 2 to 3 × 5 to 40 mm, and confined by leaf veins that eventually coalesced. To identify the pathogen, 75 leaf samples were collected from 25 fields (three leaf samples for each field) at the kernel maturity stage. Single, well-separated lesions were excised and surface-sterilized by placing them in 75% ethanol for 5 s, then disinfested in 2% sodium hypochlorite for 5 min and rinsed with sterilized water. The lesions were incubated on water agar (WA) at 24°C for 48 to 72 h to allow sporulation. Seventy-five single-conidial isolates were obtained and cultured as described in Crous (1). Morphology of the isolates was determined on plates containing maize leaf powder agar (MLPA). After 5 days, isolates produced pale brown mycelia that consisted of 3- to 4-µm-wide, septate, branched hyphae. Conidiophores were 5 to 7 × 55 to 100 µm, straight to slightly flexuous, and usually 1- to 5-septate. Conidia were average 7.5 × 68 µm, fusiform, apex subobtuse, base subtruncate, and 3- to 6-septate. These characteristics are similar to C. zeina (2). The internal transcribed spacer (ITS) region of rDNA was amplified from each of the 75 isolates using primers ITS1/ITS4 and sequenced. The same sequences were obtained and the sequence of isolate YNGLS was submitted to GenBank (Accession No. KC878692). BLAST analysis of the sequence showed 100% confirmation to C. zeina (DQ185081). Additionally, a PCR-based diagnostic test using species-specific primers (2) confirmed the identification of the 75 isolates as C. zeina. The pathogenicity of the isolates was tested on greenhouse grown maize variety Huidan 4. The test was performed on 40 plants and replicated three times. The plants were inoculated at the 10 leaf stage by injecting 2 ml of conidial suspensions (2,500 conidia ml-1) into leaf whorl using a hypodermic syringe, and control plants were injected with sterile water. Conidia were collected from 5-day-old cultures grown on MLPA and suspended in sterile water. Forty days after inoculation, all inoculated plants showed characteristic lesions on leaves, but control plants remained asymptomatic. C. zeina was reisolated from the lesions, and the identity of the reisolates was confirmed by the morphological and molecular characteristics as stated above. C. zeina was previously reported as the causal agent of maize gray leaf spot (2). To our knowledge, this is the first report of C. zeina causing gray leaf spot of maize in China. References: (1) P. W. Crous. Mycologia Memoir. 21:1, 1998. (2) P. W. Crous et al. Stud. Mycol. 55:189, 2006. (3) C. H. Lu et al. J. Southwest China Normal Univ. 37:51, 2012.

Passively Q-switched Nd:Sc0.2Y0.8SiO5 dual-wavelength laser with the orthogonally polarized output.

We have demonstrated a laser-diode pumped continuous-wave (CW) and passively Q-switched laser with a Nd:Sc(0.2)Y(0.8)SiO(5) (Nd:SYSO) crystal for the first time. In the CW operation, the laser was found to oscillate in tri-wavelength regime at 1074.8 nm, 1076.6 nm and 1078.2 nm, respectively. The maximum CW output power of 1.96 W was obtained, giving an optical-to-optical conversion efficiency of 35% and a slope efficiency of 39%. Using either Cr(4+):YAG or V(3+):YAG crystal as saturable absorber, stable passively Q-switched laser was obtained at dual-wavelength of 1074.8 nm and 1078.2 nm with orthogonal-polarization. The maximum average output power, pulse repetition rate, and shortest pulse width were 1.03 W, 50 kHz, and 24 ns, respectively. The passively Q-switched dual-wavelength laser could be potentially used as a source for generation of terahertz radiation.

Diode-pumped femtosecond Yb:CaNb2O6 laser.

We report to our knowledge a diode-pumped passively mode-locked Yb:CaNb(2)O(6) (Yb:CN) laser for the first time. Both CW and passive mode-locking operation of the laser are experimentally investigated. A maximum CW output power of 1.4 W with a slope efficiency of 20% is obtained on a 7 mm long 1.5 at.% Yb:CN crystal, while stable passive mode-locking with a commercial semiconductor saturable absorption mirror (SESAM) was achieved on a 3 mm long 3 at.% Yb:CN crystal. The mode-locked pulses have pulse width of 251 fs and an average output power of 44 mW at 1038 nm.

Evidence of dissipative solitons in Yb³âº:CaYAlO4.

Operation of an end-pumped Yb³âº:CaYAlO4 laser operating in the positive dispersion regime is experimentally investigated. The laser emitted strongly chirped pulses with extremely steep spectral edges, resembling the characteristics of dissipative solitons observed in fiber lasers. The results show that dissipative soliton emission constitutes another operating regime for mode locked Yb³âº-doped solid state lasers, which can be explored for the generation of stable large energy femtosecond pulses.

Femtosecond and continuous-wave laser performance of a diode-pumped Yb3+:CaYAlO4 laser.

The cw and femtosecond laser operations of Yb(3+):CaYAlO(4) (Yb:CYA) are demonstrated. The laser emitted a maximum cw power of 1.94 W with a slope efficiency (η(slope)) of 71% and an optical-to-optical efficiency (η(opt)) of 51%. Under mode-locking operation, the laser emitted near transform-limited pulses with 156 fs pulse width, 8.1 nJ pulse energy and 0.74 W average power. The η(slope) and η(opt) of the mode-locked laser were 37% and 20%, respectively.