Concept for power scaling by harmonic beam coaxial combination in an intra-cavity frequency doubling laser.

A new method of harmonic beam coaxial combination (HBCC) from two intra-cavity frequency doubling branches was demonstrated. Firstly, two identical nanosecond (ns) 532 nm green lasers with high power and good beam quality were created. Each green laser was constructed of an intra-cavity frequency doubling branch based on a laser diode (LD) end-pumped acousto-optical (AO) Q-switched 1064 nm Nd:YVO4 laser in a LiB3O5 (LBO) nonlinear crystal. Each branch generated about 45 W green output at a 50 kHz pulse repetition rate (PRR) with diffraction limited beam quality. The first green beam was injected into the LBO crystal in the second branch, and the pulses from the two branches did not exist simultaneously. Then, the HBCC was performed. Consequently, an 83 W combined green output power at 532 nm was obtained with a combination efficiency of 92.2%. The PRR of the HBCC pulse was doubled to be 100 kHz, with a pulse width of about 22 ns, corresponding to a single pulse energy of 0.83 mJ and a peak power of 37.73 kW. The combined beam quality factor was measured to be M x2 = 1.80 in the x direction and M y2 = 1.71 in the y direction, respectively. Moreover, many more beams could also be combined with this method for further scaling the green power.

Insights into the genetic spatial structure of Nicaraguan weedy rice and control of its seed spread.

BACKGROUND: The genetic backgrounds and occurrence patterns of weedy rice (WR, Oryza sativa) are highly diverse, and so are the challenges facing its control among countries. WR control is difficult because it is similar to cultivated rice and manual removal is one of the few options for control. Understanding the ecology of WR will aid efforts to break its life cycle and establish long-term management strategies under both irrigated and rainfed systems. RESULTS: Nicaraguan WR (NWR) plants were genetically closer to the AUS and Indica pools in terms of to genetic distance. A map of admixture coefficients suggested a pattern of long-distance dispersal and spread of NWR across Nicaragua, which has likely been facilitated by commercial activities and sharing of harvesting equipment between border cities or important trading ports and inland regions. Moreover, the NWR plants from the soil seedbank in irrigated regions showed different habitats and lower grain number per panicle compared with plants spread by seed-mediated contamination. In addition, grain indexes showed that length-to-width ratio was a better indicator than awn length for distinguishing between NWR and Nicaraguan Indica cultivars. CONCLUSION: Analysis of the population structure and habitats of NWR revealed five clusters derived from seed-mediated contamination in rainfed upland regions, plants from the soil seedbank in irrigated double-cropping regions, and pollen-mediated contamination across both regions. Field weed management before harvesting and seed purification based on the length-to-width ratio can be conducted to improve the efficiency of long-term control of WR in Nicaragua. © 2022 Society of Chemical Industry.

Plagues of Desert Locusts: Very Low Invasion Risk to China.

Recently, the most serious upsurge of the desert locust (Schistocerca gregaria) in the last 25 years is spreading across eastern Africa and southwestern Asia. Parts of the desert locust 'invasion area', namely the northern border areas of Pakistan and India, are very close to China, and whether locust swarms will invade China is of wide concern. To answer this question, we identified areas of potentially suitable habitat for the desert locust within China based on historical precipitation and temperature data, and found that parts of Xinjiang and Inner Mongolia provinces could provide ephemeral habitat in summer, but these places are remote from any other desert locust breeding areas. New generation adults of the desert locust in Pakistan and India present since April led to swarms spreading into the Indo-Pakistan border region in June, and so we examined historical wind data for this period. Our results showed that winds at the altitude of locust swarm flight blew eastward during April-June, but the wind speeds were quite slow and would not facilitate desert locust eastward migration over large distances. Simulated trajectories of desert locust swarms undertaking 10-day migrations mostly ended within India. The most easterly point of these trajectories just reached eastern India, and this is very close to the eastern border of the invasion area of desert locusts described in previous studies. Overall, the risk that the desert locust will invade China is very low.

Migratory Take-Off Behaviour of the Mongolian Grasshopper Oedaleus asiaticus.

Oedaleus asiaticus is one of the dominant species of grasshoppers in the rangeland on the Mongolian plateau, and a serious pest, but its migratory behavior is poorly known. We investigated the take-off behavior of migratory O. asiaticus in field cages in the inner Mongolia region of northern China. The species shows a degree of density-dependent phase polyphenism, with high-density swarming populations characterized by a brown morph, while low-density populations are more likely to comprise a green morph. We found that only 12.4% of brown morphs engaged in migratory take-off, and 2.0% of green morphs. Migratory grasshoppers took off at dusk, especially in the half hour after sunset (20:00-20:30 h). Most emigrating individuals did not have any food in their digestive tract, and the females were mated but with immature ovaries. In contrast, non-emigrating individuals rarely had empty digestive tracts, and most females were mated and sexually mature. Therefore, it seems clear that individuals prepare for migration in the afternoon by eliminating food residue from the body, and migration is largely restricted to sexually immature stages (at least in females). Furthermore, it was found that weather conditions (particularly temperature and wind speed at 15:00 h) in the afternoon had a significant effect on take-off that evening, with O. asiaticus preferring to take off in warm, dry and calm weather. The findings of this study will contribute to a reliable basis for forecasting migratory movements of this pest.

The year 2020, a milestone in breaking the vicious cycle of poverty and illness in China.

Marking the end of the five-year programme initiated by the Chinese Government to lift more than 70 million people out of poverty, the year 2020 is a milestone. Poverty alleviation has moved strongly forward in China and the major health indicators are now better than the average of all middle- and high-income countries. However, the dual burden of infectious and chronic diseases remains a challenge with respect to achieving the health target in the United Nations 2030 Agenda for sustainable development goals (SDGs). In 2015, about 44% of the poor population in China were impoverished by illness but already in 2018, multi-sectoral actions delivered by the Health-related Poverty Alleviation programme had reduced the number almost by half. In the past three years 15 million poor people (98% of the poor population) with infectious and chronic diseases had been treated and taken care of thanks to financial support through multiple health insurance schemes and other governmental subsidies. This article discusses the lessons learnt with regard to health-related poverty alleviation in China with special reference to those still remaining impoverished by illness. Consolidation of the achievements reached and provision of basic needs to those still disadvantaged and in poor health will require a major improvement of accessibility to, and affordability of, health services. The next step towards enhanced productivity and better living conditions will involve upgrading of the capacity of health professionals in the poor regions, promotion of coherent efforts in health-related poverty alleviation and rural revitalization measures. As an additional measure, data monitoring and research on health poverty alleviation should be strengthened as they are essential to generate the evidence and knowledge needed to support the move in the direction envisioned by the SDGs, and the new Healthy China 2030 programme.

The Early Northward Migration of the White-Backed Planthopper (Sogatella furcifera) is Often Hindered by Heavy Precipitation in Southern China during the Preflood Season in May and June.

Seasonal weather systems that establish prevailing winds and seasonal rainfall on a large scale largely determine insect migration patterns, especially for micro-insects with completely windborne migration. Recent studies indicated that the summer migration of the brown planthopper (BPH, Nilaparvata lugens) in eastern China is related to the strength and position of the Western Pacific Subtropical High-Pressure (WPSH) system and its associated wind and rainfall patterns. Compared with the BPH, the white-backed planthopper (WBPH, Sogatella furcifera) has a similar diet, analogous body size, and strong long-distance migration ability. Thus, the migration pattern for the WBPH can be speculated to be similar to that of the BPH. However, the migration pattern of the WBPH and how this pattern relates to climatic conditions have scarcely been described. Based on almost three decades of data (1977-2003), it was suggested that the WBPH in southern China (south of approximately 27° N) migrates into the middle and lower reaches of the Yangtze River after the abrupt movements of the WPSH in mid-June, similar to the BPH. By contrast, the emigration of the WBPH in southern China begins in late May. Further analysis indicated that the migration of the WBPH in late May and early June was short or unsuccessful due to heavy precipitation during the preflood season in southern China from late May to middle June. The results herein demonstrate the differences in migration patterns between two rice planthoppers in the eastern Asia migration arena. We also provide new information that could assist with forecasting outbreaks and implementing control measures against these migratory pests.

Gastric cancer incidence and mortality in Zhuanghe, China, between 2005 and 2010.

AIM: To investigate the incidence and mortality of gastric cancer (GC) in Zhuanghe region, northeast China and the influencing factors for their changing trends. METHODS: All new cancer cases and deaths registered from 2005 to 2010 in Zhuanghe County were reviewed. The annual GC cases, constituent ratio, crude rates, age-standardized rates, their sex and age distribution and temporal trends were assessed. The method of annual percentage change (APC) was used to estimate the trends of GC. RESULTS: Altogether 2634 new cases of GC and 1722 related deaths were registered, which accounted for 21.04% and 19.13% of all cancer-related incidence and deaths, respectively. The age-standardized incidence rate steadily decreased from 57.48 in 2005 to 44.53 in 2010 per 10(5) males, and from 18.13 to 14.70 per 10(5) females, resulting in a APC of -5.81% for males and -2.89% for females over the entire period. The magnitude of APC in GC mortality amounted to -11.09% and -15.23%, respectively, as the age-standardized mortality rate steadily decreased from 42.08 in 2005 to 23.71 in 2010 per 10(5) males, and from 23.86 to 10.78 per 10(5) females. Females had a significantly lower incidence (a male/female ratio 2.80, P < 0.001) and mortality (a male/female ratio 2.30, P < 0.001). In both genders, the peak incidence and mortality occurred in the 80-84 years age group. The age-standardized mortality/incidence ratio also decreased from the peak of 0.73 in 2005 to 0.53 in 2010 for males, and from 1.32 to 0.73 for females. CONCLUSION: Encouraging declines of incidence and mortality of GC were observed in Zhuanghe region between 2005 and 2010, possibly due to the economic development and efficient GC control strategies.

In vitro-activated tumor-bearing host T cells and the effectiveness of tumor vaccine immunotherapy.

BACKGROUND AND OBJECTIVE: Vaccination during periods of lymphopenia may facilitate immune responses to weak self-antigens and enhance antitumor immunity. The objective of this study was to determine the effectiveness of tumor vaccine immunotherapy combined with immune reconstruction using tumor-bearing host immune cells in lymphopenia, and to investigate the role of tumor-bearing host T cells activated in vitro during immunotherapy. DESIGN AND SETTING: Animal study conducted in the First Affiliated Hospital of Xi'an Jiaotong University from January 2009 to January 2010. PATIENTS AND METHODS: Lymphopenia was induced by cyclophosphamide. A reconstituted immune system with different syngeneic lymphocytes was employed, including lymphocytes from naïve rats (unsensitized group), tumor-bearing rats (tumor-bearing group), and tumor-bearing rats activated in vitro (activated group). All rats were immunized with granulocyte-macrophage colony-stimulating factor (GM-CSF)-modified NuTu-19 ovarian cancer (GM-CSF/NuTu-19) cells. Tumor vaccine-draining lymph nodes (TVDLNs) were harvested, and then stimulated to induce effector T cells (T(E)). T(E) were then adoptively transferred to rats bearing a 3-day pre-established abdominal tumor (NuTu-19), and the survival rate was calculated. RESULTS: Compared with the unsensitized group, the levels of interleukin-2 (IL-2) were significantly lower in the tumor-bearing group, whereas that of IL-4 were significantly higher (P<.05). The number of CD4+ T cells secreting interferon-γ and the specific cytotoxicity of CD8+ cytotoxic T lymphocytes were significantly lower (P<.05). The survival was significantly higher in the activated group compared with the other groups. CONCLUSIONS: Lymphocytes from tumor-bearing rats activated in vitro can effectively reverse the immunosuppressive effects of tumor-bearing hosts.

[Evaluation of immune reconstitution with in vitro-activated T cells from a tumor-bearing host].

AIM: To evaluate the reconstituted immune system with in vitro-activated T cells from tumor-bearing rats coupled with ovarian cancer vaccination. METHODS: Fischer 344 female rats were injected with cyclophosphamide (CY) as a lymphopenia (LP) model. The immune systems of the rats were reconstituted with in vitro-activated T cells from the same individuals. GM-CSF-modified ovarian cancer cells lines (NuTu-19) were injected within 24 h after immune reconstitution. The tumor vaccine draining lymph nodes (TVDLN) were harvested 8-10 days after vaccination and analyzed by FACS. The proliferative capacity of dendritic cells (DCs) was measured by the levels of MHC-II and CD86 molecules. The activation of T cells was monitored by the percentage of FITC-CD4 and PE-CD8 cells. The biological function of DCs such as processing and presenting antigens was assayed by immature DCs' phagocytosis of FITC-Dextran. RESULTS: Immune reconstitution with in vitro-activated T cells produced significantly more DCs, T cells and functionally enhanced immature DCs out of TVDLN. CONCLUSION: Reconstituting immune system with in vitro-activated T cells from a tumor-bearing host coupled with ovarian cancer vaccination during lymphocytopenia may selectively expand and activate particular T cells and DCs, leading to augmentation of anti-tumor immunity.

[Animal experiments of immunotherapy with ovarian tumor vaccine during lymphopenia induced by chemotherapy.].

OBJECTIVE: To explore the mechanisms and effects of adoptive immunotherapy with ovarian cancer vaccine modified by GM-CSF gene which was used after immunologic reconstitution during lymphopenia induced by chemotherapy. METHODS: Lymphopenia was induced by chemotherapy with cyclophosphamide. The immune reconstituted model was built in rats. The tumor vaccine draining lymph nodes were harvested after the ovarian cancer cells NUTU-19 modified by GM-CSF gene were injected. The effector T cells (T(E)) were got after being stimulated and amplified. Enzyme-linked immunosorbent assay was used to detect the level of interleukin (IL)-2 and IL-4 secreted by T(E). Intracellular cytokine staining was used to determine frequency of tumor-specific T(E). Fluorescence-activated cell sorting (FACS) was used to detect the special cytotoxicity of T(E) killing target cells. The survival period of rats bearing pre-established abdominal ovariam carcinoma after being adoptively transferred by T(E) was observed. RESULTS: Compared with those in control group, the significant higher levels IL-2 [(65.7 +/- 4.0) pg/ml] and lower levels IL-4 [(277 +/- 49) pg/ml] were observed in chemotherapy-immune reconstitution-vaccine immunization group. The amount of CD(4)(+) T cells secreting interferon-gamma (13.0 +/- 2.1)% were also significantly increased. The rate of the special cytotoxicity of killing T cells (86.5 +/- 1.1)% was markedly improved. The survival period of rats (110 +/- 16) days was increased in chemotherapy-immune reconstitution-vaccine immunization group. CONCLUSIONS: The combined immunotherapy of chemotherapy-immune reconstitution-tumor vaccine immunotherapy may increase the frequency and function of specific tumor T(E). The specific cytotoxicity is increased and the weak reaction of T(E) to tumor is improved, which showed that this therapy can enhance immune reaction.