Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Toroidal soft x-ray array on the EXL-50 spherical tokamak

A toroidal soft x-ray array system for spectrum and intensity measurements on the EXL-50 spherical tokamak is described. Silicon drift detectors and digital multichannel analyzers are adopted for all 21 channels of the array, and an average energy resolution of 147 eV at 5.89 keV has been achieved at count rates over 500 kcps. In total, 20 channels of the array are symmetrically observed in both co- and counter-current directions on the EXL-50 mid-plane with a spatial resolution of around 10 cm, and the remaining one serves as a background reference channel. Tungsten emissions from tungsten coating of the limiters on the central post are observed. The influence of hard x rays on measured soft x-ray spectra and system operation is discussed.

[Cardiovascular toxicities associated with immune checkpoint inhibitors]

With the continuous development of cancer treatment, the immune checkpoint inhibitors have been applied to the treatment of a variety of malignant tumors, which improved the patient's survival time and quality of life. However, immune-related adverse reactions occur inevitably. Like chemotherapeutics and targeted drugs, immunosuppressants can also cause cardiovascular events that affect the mortality of cancer patients. With the extension of the survival time of cancer patients, it will increasingly become a key factor which affects the prognoses of these diseases. This review focuses on the cardiotoxic mechanism, clinical manifestation, and future direction of immune checkpoint inhibitors during cancer treatment.

[Peripheral T-cell lymphoma with follicular helper of T cell phenotype of Waldeyer's ring: a clinicopathological and genetic study of eight cases]

Objective: To study the clinicopathologic and genetic features of Waldeyer's ring peripheral T-cell lymphoma with follicular helper T cell immunophenotypes (wPTCL-TFH), with comparison to the nodal peripheral T-cell lymphoma with TFH immunophenotypes (nPTCL-TFH) and angioimmunoblastic T-cell lymphoma (AITL), as to know this rare tumor better. Methods: The clinical data, histopathology features, EBV positivity, T cell clonality and IDH2(R172) gene mutation in 8 cases of wPTCL-TFH were collected at the First Affiliated Hospital of Zhengzhou University from December 2015 to April 2019, and analyzed by immunohistochemistry, in situ hybridization, TCR gene rearrangement (BIOMED-2) and Sanger sequencing.Follow-up data were obtained by telephone. Results: There were 6 males and 2 females with a median age of 62.5 years (age ranging from 30 to 75 years). All patients had neither fever nor skin manifestations, but were all found mucosa thickened or mass of waldeyer's ring with multiple lymph nodes enlarged by PET-CT/CT scans. Five of the 7 patients were at advanced stages (Ⅲ/Ⅳ stage). Microscopically, the mucosa was infiltrated diffusely and characteristically by numerous small-medium sized lymphocytes, lacking polymorphous inflammatory background and extra-follicular expansion of follicular dendritic cell networks (FDC networks). The clear T cells presented in 5 cases. Ulcers on mucosal surfaces (6 cases) and local-extensive loss of intramucosal glands (7 cases) were commonly noted. Granulomas composed of epithelioid histiocytes were observed in 2 cases. Immunohistochemically, all the tumor cells expressed CD4 and at least 2 types of follicular helper of T cell (TFH) markers: PD-1 (8/8), bcl-6 (8/8), CXCL13 (7/8) and CD10 (1/8). Most of the cases (6 cases) expressed CD30. EBV positive appeared in 4 cases. All 8 cases were T cell monoclonal. IDH2(R172) were wild-type in 6 cases. One patient died at the follow-up time on 18 months; the other 7 survived (the follow-up time varied from 3 to 10 months). Conclusions: wPTCL-TFH is rare, and its clinicopathological features are similar to nPTCL-TFH which may be the manifestation of the same disease at different stage, and partly overlapped with AITL. The differential diagnosis from PTCL-NOS is necessary and comprehensive analyses of clinical, morphological, immunohistochemical and genetic features can help make a correct diagnosis.

[Changes of retinal structure after systemic immunosuppressive treatment in eyes with Vogt-Koyanagi-Harada disease]

Objective: To assess structural changes in retina after systemic immunosuppressive treatment in Vogt-Koyanagi-Harada (VKH) disease using spectral-domain optical coherence tomography (SD-OCT). Methods: The clinical data of 17 VKH cases (34 eyes) who consecutively attended the Beijing Tongren Hospital between December 2015 and December 2019 were retrospectively reviewed. All the patients had acute or subacute onset, and underwent high-dose systemic corticosteroid and/or immunosuppressive treatment, with a followed-up time of at least 6 months. At the end of follow-up, the intraocular inflammation was controlled, and oral prednisone was withdrawn or being adjusted to less than 10 mg/day. The SD-OCT features of the included eyes were analyzed before treatment, 1 week, 1 month and 3 months after treatment, and at the last visit. Results: A total of 17 cases (34 eyes; 6 males and 11 females) were included, with an age of (42.2±10.6) years, and were followed up for (9.4±3.3) months. At 1 week after initiating treatment, the percentage of the eyes with extensive/multiple or multifocal retinal detachment in the macular region, membranous structures and intraretinal cysts, and undulations and bumps of retinal pigment epithelium (RPE) decreased (5.9% vs 100%, 2.9% vs 47.1%, 5.9% vs 70.6%, 11.8% vs 58.8%, respectively, all P<0.001). There was statistical significant difference of the percentage of ellipsoid zone and external limiting membrane (ELM) disruptions before treatment, at 3 months and the last visit (100% vs 35.3%, 64.7% vs 52.9%, 41.2% vs 26.5%, respectively, all P<0.001). At the last visit, there were statistical significant differences of the best corrected vision acuity (BCVA) between the intact ellipsoid zone group (20 eyes) and the discontinuous group (14 eyes), as well as between the intact ELM group (25 eyes) and the discontinuous group (9 eyes), respectively [0 (0, 0.05) vs 0.10 (0.03, 0.33) (log MAR), P=0.004; 0 (0, 0.07) vs 0.22 (0.05, 0.40) (log MAR), P=0.005]. Conclusions: The edema of choroid and retina subsided obviously at 1 week after initiating treatment. The extent of damage and recovery ability of ellipsoid zone and ELM were different before treatment, at 3 months and the last visit. At the last visit, the outer retinal layers failed to recover completely in some patients, and were related to the BCVA.

[Clinicopathological and molecular features of pulmonary enteric adenocarcinoma]

Objective: To investigate the clinicopathological and molecular characteristics of pulmonary enteric adenocarcinoma (PEAC). Methods: The clinical and pathological data of 19 cases of PEAC in the Affiliated Cancer Hospital of Zhengzhou University were retrospectively collected from 2015 to 2019. Immunohistochemistry (IHC) was used to detect the relevant immunophenotypes, amplification refractory mutation system (ARMS) and fluorescence in situ hybridization (FISH) were used to detect the expression of EGFR, KRAS and ALK genes. The patients were followed up, and the relevant literature was reviewed and analyzed. Results: There were 19 cases, including 10 males and 9 females, with a mean age of 58 years (range 33-71 years). Microscopically, the tumors showed moderately to highly differentiated adenoid and/or papillary growth patterns. The tumor cells were highly columnar and sometimes showed pseudostratification. Inflammatory necrosis and scattered nuclear fragmentation were seen in some glandular lumens. IHC showed variable expression of CK7 (19/19), TTF1 (8/19), Napsin A (6/19), villin (17/19), CK20 (16/19) and CDX2 (10/19). Molecular testing showed KRAS mutation in nine cases (9/19), EGFR mutation in one case (1/19), and positive ALK split signal in one case (1/19). In the literature, the reported mutation rate of KRAS in PEAC was much higher than that of EGFR and ALK. All 19 cases underwent surgical resection and 11 cases were subjected to chemotherapy or radiotherapy. Conclusions: PEAC is a rare variant of invasive pulmonary adenocarcinoma, and has similar histological and cytological features to that of colorectal adenocarcinoma. However, detailed medical history, histologic heterogeneity, an IHC combination of CK7(+)/villin(+) and high KRAS mutation rate are the key points of diagnosis. The prognosis needs long-term follow-up and big data statistics.

[Effects and mechanism of rat epidermal stem cells treated with exogenous vascular endothelial growth factor on healing of deep partial-thickness burn wounds in rats]

Objective: To explore the effects and mechanism of rat epidermal stem cells (ESCs) that were treated with exogenous vascular endothelial growth factor (VEGF) on the healing of deep partial-thickness burn wounds in rats. Methods: ESCs were isolated and cultured from the trunk skin of a 3-month-old female Sprague-Dawley (SD) rat. The third passage of cultured cells in the logarithmic growth phase was used in experiments (1)-(3). (1) The cells were routinely cultured in keratinocytes-specified serum-free medium (K-SFM) (the same routine culture condition below). The morphology of cells cultured for 3 and 5 days was observed under the inverted optical microscope. (2) After 24 hours in routine culture, the expression of cell surface markers CD44, CD45, CD11b, and CD11c was detected by flow cytometer, with triplicate samples. (3) Four batches of cells were collected, and each batch was divided into VEGF group or blank control group according to the random number table. The cells in blank control group were routinely cultured, while the cells in VEGF group were cultured in K-SFM containing VEGF in the final mass concentration of 10 ng/mL. The protein expressions of cytokeratin 19 (CK19) and CK10 in cells cultured for 10 days were detected by Western blotting. The Nanog mRNA expression in cells cultured for 0 (immediately), 2, 4, 6, 8, and 10 day (s) was detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. The absorbance value was detected with cell counting kit-8 in cells cultured for 2, 4, 6, 8, and 10 days. The clone number of more than 50 cells was observed and counted under the optical microscope in cells cultured for 10 days, and the cell colony formation rate was calculated. Three samples at each time point was analysed. (4) Thirty-six 3-month-old SD rats (either male or female) were used for the study, and two deep partial-thickness burn wounds (10 mm in diameter) were created in each rat by pressing a 100 ℃ electric iron plate on symmetric dorsal side. According to the random number table, the injured rats were divided into VEGF+ ESCs group, ESCs alone group, and blank control group, with 12 rats and 24 wounds in each group. From 0 (immediately) to 2 day (s) after injury, 20 μL phosphate buffer solution (PBS) was injected into each wound in the three groups in one time, once a day, with the solution in VEGF+ ESCs group containing 0.8×10(6) cells/mL of ESCs treated by 10 ng/mL VEGF for 10 days, the solution in ESCs alone group containing 0.8×10(6) cells/mL of ESCs without any treatment, and the solution in blank control group being PBS only. On post first injection day (PFID) 0 (immediately), 3, 7, and 14, three rats from each group were taken respectively according to the random number table for wound healing assessment, and the wound healing rates on PFID 3, 7, and 14 were calculated. The mice at each time point were sacrificed with wound tissue harvested for histology, and the skin structure was observed by hematoxylin-eosin staining. Data were statistically analyzed with independent sample t test, analysis of variance for factorial design, least significant difference test, and Bonferroni correction. Results: (1) By day 3 in culture, cells distributed in slowly-growing clusters. By day 5, the clusters were large and round, in which the cells mainly with large and round nuclei and little cytoplasm were observed. The above results were consistent with the morphological characteristics of ESCs. (2) The positive expression rate of CD44 was (94.3±1.2) %, and the expressions of CD45, CD11b, and CD11c were negative. The cells were confirmed as ESCs. (3) Compared with those of blank control group, the protein expression of CK19 in the cells of VEGF group was significantly increased after 10 days in culture (t=3.756, P<0.05), while the protein expression of CK10 was significantly decreased (t=3.149, P<0.05). Compared with those of blank control group, the Nanog mRNA expression in the cells cultured for 0 and 2 day (s) and absorbance values of the cells cultured for 2 and 4 day (s) were not significantly changed in VEGF group (t=0.58, 0.77, 0.53, 3.02, P>0.05), while the Nanog mRNA expression in the cells cultured for 4, 6, 8, and 10 days and absorbance values of the cells cultured for 6, 8, and 10 days were significantly increased in VEGF group (t=6.34, 5.00, 5.58, 4.61, 5.65, 10.78, 15.51, P<0.01). After 10 days in culture, the cell colony-forming rate in VEGF group was (56.4±1.3) %, significantly higher than (31.5±1.3) % of blank control group (t=13.96, P<0.01). (4) The burn wounds of rats in the three groups were confined to the superficial dermis of the skin on PFID 0. On PFID 3, normal skin tissue at wound margins slightly contracted in the rats of VEGF+ ESCs group, which was earlier than that in the other two groups. On PFID 7, the newly generated epidermis covered most parts of the rat wounds in VEGF+ ESCs group, and some of the epithelium crawled around the rat wounds in ESCs alone group, but no obvious epithelialization was observed in the rat wounds in blank control group. On PFID 14, the rat wounds in VEGF+ ESCs group were basically healed, while some parts of the rat wounds were unhealed in ESCs alone group, and most parts of the rat wounds were unhealed in blank control group. On PFID 3, the wound healing rates of rats in the three groups were similar (P>0.05). On PFID 7 and 14, the wound healing rates of rats in ESCs alone group, respectively (26.0±2.0) % and (64.4±4.7) %, were obviously higher than (12.4±1.1) % and (29.1±3.3) % of blank control group (P<0.01), all of which were obviously lower than (41.0±2.4) % and (91.3±3.5) % of VEGF+ ESCs group (P<0.01). On PFID 3, infiltration of a large number of inflammatory cells were observed in the rat wounds in VEGF+ ESCs group, which was earlier than those in the other two groups. On PFID 7, a large number of endothelial cells were observed in the rat wounds in VEGF+ ESCs group, while proliferation of a few endothelial cells were observed in the rat wounds in ESCs alone group, and a large number of inflammatory cells infiltrated the rat wounds in blank control group. On PFID 14, the newly generated epidermal cells covered nearly all the rat wounds in VEGF+ ESCs group and most parts of the rat wounds in ESCs alone group, while a large number of endothelial cells were observed and the newly generated epidermal cells covered some parts of the rat wounds in blank control group. Conclusions: ESCs of rats treated with exogenous VEGF can promote the healing of deep partial-thickness burn wounds in rats, which may be related to VEGF's roles in promoting the proliferation of ESCs and reducing its differentiation level, so as to maintain the potency of stem cells.

Evaluation and comparison of the diagnostic performance of routine blood tests in predicting liver fibrosis in chronic hepatitis B infection

Background & aims: Biopsy is the gold standard for staging liver fibrosis, but it may be accompanied by complications. As an alternative, non-invasive markers such as transient elastography (for liver fibrosis) and certain combinations of routine blood markers (liver function tests, full blood count) have been developed although their clinical significance remains controversial. Here, we compare the diagnostic values of non-invasive markers for liver fibrosis in patients with chronic hepatitis B infection. Methods: Transient elastography and routine laboratory tests were performed in 196 patients. Diagnostic performances were compared and were assessed based on the area under the curve (AUC) of a receiver operating characteristic (ROC) analysis. Results: Elevated GGT to platelet ratio (GPR), the fibrosis index FIB-4 [based on age, AST, platelets and ALT], platelet to lymphocyte ratio (PLR) and total bilirubin were independent predictors of liver stiffness defined by transient elastography (all P < 0.001). The AUCs of GPR in predicting both advanced fibrosis and cirrhosis were significantly larger than that of FIB-4 (P = 0.037 and P = 0.008, respectively) and AST-to-platelet ratio index (APRI) (P = 0.008 and P = 0.005). FIB-4, APRI and red cell volume distribution width-to-platelet ratio (RPR) had similar diagnostic values in discriminating different levels of liver fibrosis. Conclusions: GPR showed the best diagnostic value and RPR and PLR are easily available and inexpensive markers in evaluating fibrosis and cirrhosis. The diagnostic values of these laboratory markers are useful in diagnosing advanced fibrosis or cirrhosis, and in confirming the different levels of liver fibrosis.

[Rapamycin affect the apoptosis of splenic CD4+CD25+ regulatory T cells of mouse severe aplastic anemia model]

目的

探讨雷帕霉素（Rapamycin, RAPA）对重型再生障碍性贫血（SAA）模型小鼠CD4⁺CD25⁺ Treg细胞凋亡情况的影响及可能的机制。

方法

以近交系雌性BALB/c小鼠作为对照（对照组），应用IFN-γ腹腔注射联合白消安灌胃的方法建立SAA小鼠模型（SAA组），并使用RAPA腹腔注射5 d治疗SAA小鼠（RAPA组）。骨髓活检病理学检查观察各组小鼠的骨髓造血组织变化；免疫磁珠分选出各组小鼠脾脏Treg细胞，用流式细胞术检测其凋亡率；Western blot法检测各组小鼠脾脏Treg细胞的Akt、磷酸化（p）-Akt、Stat3、p-Stat3的表达水平；收集各组小鼠外周血和脾脏中单个核细胞，用流式细胞术检测CD4⁺CD25⁺Foxp3⁺ Treg细胞的比例变化。

结果

与对照组相比，SAA组造血细胞明显减少，且造血细胞被大量的脂肪组织所代替，RAPA组造血细胞亦明显减少，可见大量脂肪细胞；对照组、SAA组、RAPA组小鼠胫骨骨髓造血组织面积分别为（94.25±4.20）%、（7.00±2.00）%、（9.75±1.83）%，差异有统计学意义（Welch F=1 441.822，P<0.001）；RAPA组略高于SAA组[Δx=2.15%（95%CI 0.15%~5.35%），P=0.037]。对照组、SAA组、RAPA组脾脏Treg细胞凋亡率分别为（19.84±1.39）%、（29.85±2.72）%、（22.39±3.71）%，差异有统计学意义（F=18.338，P<0.001）；RAPA组Treg细胞凋亡率明显低于SAA组。RAPA组脾脏Treg细胞中Akt、Stat3的表达水平高于SAA组，而p-Akt和p-Stat3表达水平低于SAA组（P值均<0.05）。SAA组、RAPA组的脾脏CD4⁺CD25⁺Foxp3⁺/CD4⁺CD25⁺、CD4⁺CD25⁺Foxp3⁺/CD4⁺细胞比例均低于对照组，且RAPA组明显高于SAA组（P值均<0.017）。

结论

IFN-γ联合白消安诱导的SAA模型小鼠脾脏Treg细胞存在过度凋亡现象，而RAPA可能通过抑制Treg细胞内Akt及Stat3的磷酸化上调Foxp3的表达，从而抑制Treg细胞的凋亡。

[Anemia status of Chinese rural women of reproductive age in 2012]

Objective: To study the hemoglobin concentration, anemia status and its determinant factors among Chinese rural women of reproductive age in 2012. Methods: This was a cross-sectional study. The data was obtained from the National Free Preconception Health Examination Project (NFPHEP). A total of 712 101 Chinese rural reproductive age women aged 21-49 years old who came from 193 counties of 30 provinces were included. The demographic characteristics were obtained from questionnaires. Hemoglobin concentration was measured using the cyanomethemoglobin method. The definition of anemia we used was recommended by World Health Organization, and was adjusted according to altitude level. The hemoglobin concentration level, the prevalence of anemia and its 95% CI was calculated. Determinant factors of anemia such as demographic characteristics and histories of pregnancy and miscarriage were analyzed using logistic regression. Results: In 2012, the level of hemoglobin concentration in Chinese rural women of reproductive age was (127.77±13.47) g/L, with the lowest in 21-24 years group, which was (127.54±13.54) g/L, and highest in 35-39 years group, which was (128.39±14.12) g/L. In terms of region, the hemoglobin concentration level was lowest in central south, which was (125.79±12.00) g/L, and highest in southwest, which was (129.91±14.37) g/L. The prevalence of anemia in Chinese rural women of reproductive age was 24.80%, with the highest seen in 21-24 years, which was 25.92% (95% CI: 25.74%-26.11%), and lowest in 30-34 years, which was 23.61% (95% CI: 23.37%-23.85%). The prevalence in northwest (28.31%, 95% CI: 28.01%-28.61%) was the highest among all regions, and the prevalence in east (20.88%, 95% CI: 20.68%-21.09%) was the lowest. Conclusions: The prevalence of anemia in Chinese rural reproductive age women was 24.80% in 2012. The anemia prevalence was higher among women who were young, had low educational level, and lived in northwest region.

[Safety of resuscitation with hydroxyethyl starch 130/0.4 in hemorrhagic shock rats]

Objective: To evaluate the safety of resuscitation with hydroxyethyl starch 130/0.4 during the early stage of hemorrhagic shock. Methods: Total of 120 healthy male SD rats of 2 to 3 months of age were selected as the study sample (weighed from 250 to 290 g), all the rats were numbered by staining.After that, the rats were divided into 12 groups by using random number table method: sham group (S group), no liquid resuscitation group (NF group), lactated Ringer's resuscitation group (LR group), HES resuscitation group (HES group). At the same time, the LR and HES resuscitation groups were divided into five subgroups with a concentration of 7.5, 15, 30, 60 and 90 ml·kg(-1)·h(-1,) respectively.The model of uncontrollable hemorrhagic shock was created by the method of exsanguination plus tail-cuffing.Fluid resuscitation was started 30 minutes after the exsanguination and continued for 60 min after transfusion for 15 min.The observation was continued for 330 min.At the end of observation, all rats were sacrificed and blood was collected from the rats to determine the thromboelastograms and the maximum amplitude and related parameters, as well as platelet counts, blood urea nitrogen, creatinine, urinary and renal injury molecules, and neutrophil gelatinase-associated apolipoprotein levels.Rat lung tissue specimens were collected and wet weights of the right lung and dry weights after drying were measured.The data were compared by using one-way analysis of variance (ANOVA), LSD-t test or Dunnett-t test. Results: ANOVA analysis showed that there was no significant difference in mean artery pressure (MAP) values between groups at the beginning of fluid resuscitation (F=0.934, P=0.245). At the end of fluid resuscitation, the MAP of HES90 group was (40±9) mmHg, which was lower than that in other groups.Compared with other groups, the HES90 group had higher blood loss and blood transfusion rate.There was no significant differences in platelet counts between the HES group and the LR group at 330 min (t=0.987, P>0.05), but the maximal amplitude (MA) of the thrombelastogram (TEG) was lower in the HES90 group than that in the S group (t=2.354, P<0.05). No significant difference was detected in blood urea nitrogen and serum creatinine levels between the HES, LR group and the S group (t=1.098, 0.895, both P>0.05). The total amount of urinary kidney injury molecule 1 (Kim-1) in the HES90 and NF groups increased, neutrophil gelatinase-associated apolipoprotein (NGAL) concentration and urinary NGAL levels were significantly higher than those in other groups, and the difference were statistically significant (t=3.532-11.209, all P<0.05). Conclusion: Small to moderate doses of HES130/0.4 during hemorrhagic shock is more effective and safer than the same dose of LR.

[Effects of exogenous growth regulators on plant elongation and carbohydrate consumption of rice seedlings under submergence.]

This experiment was conducted to evaluate the effects of exogenous regulators on plant elongation and carbohydrate consumption of rice seedlings under submergence. IR64 and IR64-Sub1 with submergence tolerance gene Sub1 were used. Twenty-day-old seedlings were sprayed with 1-aminocyclopropane-1-carboxylic acid (ACC), paclobutrazol (PB), gibberellic acid (GA), or distilled water (as control) two days prior to the submergence. Plants were completely submerged and water depth was maintained for 0, 4, 8, 12, 16 days respectively in tanks. The plants were allowed to recover for seven days after submergence. We investigated the effects of ACC, PB, and GA on the survival percentage, shoot elongation, chlorophyll degradation and recovery, as well as non-structure carbohydrate (NSC) consumption. The results showed that complete submergence resulted in significant elongation of plant shoots, rapid decline of SPAD, and quick depletion of soluble sugars in leaves. However, the initial NSC content in shoots of IR64-Sub1 was higher than that of IR64, and the consumption rate during submergence was lower, and the starch content in shoots maintained after submergence was higher. PB could significantly enhance rice seedling survival by reducing plant elongation, chlorophyll degradation and NSC consumption, and the effect of PB pretreatment on IR64-Sub1 was more pronounced. Conversely, GA increased plant elongation, leaf chlorophyll degradation and depletion of NSC, which resulted in the lowest recovery capability and survival percentage. However, the inhibition of GA on submergence tolerance of IR64-Sub1 was much poorer compared with IR64. Plant elongation treated by ACC was much lower than by GA. In conclusion, PB could restrain plant elongation effectively, retarding chlorophyll degradation, decelerating NSC consumption and retaining more NSC after de-submergence. The results suggested that PB could increase rapid recovery of rice after submergence stress which was of significance in alleviating flood and waterlogging injury in flash-flood-prone areas.

Effects of the reduction of controlled-release urea application on nitrogen leaching in double cropping paddy field

Nitrogen (N) leaching is a major pathway of N losses in paddy fields. Here, an experiment was conducted to assess the effects of the reduction of controlled-release urea application on grain yield and N leaching in a double-cropping paddy field. Fertilization treatments included zero-N (CK, control, 0 kg N·hm^-2), conventional urea (CU, 180 kg N·hm^-2), and four polymer-coated urea fertilization levels, i.e., 1.0CRU, 0.9CRU, 0.8CRU, 0.7CRU, which represented 0, 10%, 20% and 30% reduction of fertilizer inputs relative to CU, respectively. Leachate was collected at the soil depth of 60 cm using field leakage pool method. Nitrogen leaching peaked shortly after fertilization, implying that measures should be taken to prevent N leaching in the early period. Nitrogen losses from leaching were 42.3 kg N·hm^-2 for 0.8CRU, and by 37.7 kg N·hm^-2 for 0.7CRU, significantly lower than the leaching in CU (53.9 kg N·hm^-2). Nitrogen leaching in 0.7CRU was significantly lower than that in 1.0CRU (51.3 kg N·hm^-2). 11.9%-13.5% of the fertilizer N was lost via leaching across the six treatments with comparable N loss rates. Rice yields, N utilization efficiency and N harvest index were significantly higher in 0.8CRU and 0.7CRU relative to CU. Our findings suggested that the use of CRU would permit a reduction in N application by 20%-30%, which could maintain the rice yield and obtain a reduction in N leaching.

[Analysis on cardio-metabolic related risk factors in farmers of 15 provinces in China]

Objective: To analyze the prevalence and co-prevalence of cardio-metabolic related risk factors in farmers aged ≥18 years in China, to explore the influence of population economic factors on them. Methods: A total of 3 367 farmers, including fishermen or hunters, aged ≥18 years were selected as study subjects from the database of Nutritional Status and Health Transition of Chinese Residents Project in 2015. Basic information (age, gender), data on anthropometric (body height, weight and waist size), blood biochemical and socioeconomic (occupation, income, education level and living area) were included. According to the definition of the metabolic syndrome released by the International Diabetes Federation (IDF) in 2005, five cardio-metabolic risk factors appeared as central obesity, increased triglycerides, decreased HDL-C, increased blood pressure and increased plasma glucose. Co-prevalence of risk factors was defined as detecting 2 or more risk factors in a person at the same time. Multivariate logistic regression model was used to analyze the relationship between socioeconomic factors and metabolic risk factors. Results: In 3 367 framers of 15 provinces (autonomous region and municipality), the prevalence rates of central obesity, increased blood pressure, increased plasma glucose, increased triglycerides and decreased HDL-C were 51.8%, 59.0%, 17.0%, 25.5% and 38.7% respectively. Multivariate logistic regression analysis showed that the risks for central obesity (OR=3.69, 95%CI: 3.17-4.28) and decreased HDL-C (OR=3.28, 95%CI: 2.81- 3.82) were higher in women than in men, and the risks for increased blood pressure (OR=0.73, 95%CI: 0.63-0.84), increased blood glucose (OR=0.80, 95%CI: 0.67-0.97) were lower in women than in men. Age was positively correlated with the prevalence or co-prevalence of metabolic risk factors (trend P<0.05). Framers in western China had obviously lower risk for central obesity compared with farmers in central China. No significant correlation was found between farmers' income level, education level or the prevalence of metabolic risk factors. Conclusion: In 15 provinces of China, the prevalence of at least 1 kind of cardio-metabolic risk factor was found in 85.5% of the farmers, and the co-prevalence of cardio-metabolic risk factor was found in 60% of farmers. The prevalence and co-prevalence of cardio-metabolic risk factors were significantly associated with age and gender. It is suggested to take targeted nutritional intervention and health education according to the distribution characteristics of prevalence and co-prevalence of cardio-metabolic factors and strengthen the early prevention and control programs of the diseases.

[Preliminary study on the automatic preparation of dental implant socket controlled by micro-robot]

Objective: To analyze the quantitative relationship between the number of layers of laser pulses and the amount of step in ultra-short pulse laser cutting of cortical bone, optimize the robot's vertical single stepping parameters, and to explore the feasibility of automatic preparation of dental implant cavity using robot controlling ultra-short pulse laser, in order to lay the foundation for automated dental implant surgery. Methods: Eight pig ribs were segmented into to make 16 specimens. Using the robotic surgical system and path planning software independently developed by our group, circular holes with a diameter of 4 mm were cut two-dimensionally in the rib segments to obtain the quantification relationship of the number of laser pulse layers (n) and the depth of two-dimensional (2D) cutting (d). When conducting the three-dimensional (3D) cutting procedure, the number of pulse layers were set to 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 layers, the vertical single step amount was an integer value corresponding to the results of 2D cutting depth, and the number of pulses (n') corresponding to the minimum difference between the theoretical depth of cut and the actual depth of cut was obtained. The n' was taken as the most suitable single step pulse layer, the rib segment was cut, and the depth of single cut was measured while the integer value was taken as the most appropriate vertical single step amount (d'). The vertical parameters of laser single stepping were set as n' layer pulse and d' μm step size. The 3D cutting produces a cylindrical cavity with a diameter of 4 mm and a height of 2 mm to evaluate the 3D cutting accuracy (the difference between the measured value and the theoretical value of cutting diameter or depth). Ten 4 mm×3 mm implant holes were automatically prepared on the bilateral femurs of 5 Japanese big white rabbits, and ten 4 mm×3 mm implants made by 3D printer were artificially implanted, and the preparation effect of the implant cavities was evaluated. Results: The quantitative relationship curve between the number of laser pulses (n) and 2D depth of cut (d) showed a linear upward trend. The linear fitting obtained the quantitative relation function formula d=9.278 4 n±26.763 0, R(2)=0.988 9. The optimum number of single step pulse layers was 5 layers, and the vertical single step amount was 50 μm, so as to set the vertical parameters of a single step of a 3D cutting, and the 3D cutting diameter accuracy was (3.98±2.87) μm, with a depth accuracy of (15.42±5.44) μm. Automated preparation of 10 implant cavities on the femur of the rabbit were completed. When the implants were placed into the implant cavities, there was resistance, but they were fully seated and primary stability has been achieved after seating implant placement. Conclusions: The method of non-contact automatic preparation of dental implant cavities using robot controlling ultra-short pulse laser is feasible. By optimizing the single cutting process parameters, precise control of laser cutting cortical bone can be realized.

A 3-year experience of a simple, novel technique for accurate ostial/non-ostial coronary stenting: The buddy balloon anchor stent technique

OBJECTIVE

To evaluate the safety and efficacy of a new technique for accurate ostial/non-ostial coronary stenting in percutaneous coronary intervention (PCI).

BACKGROUND

Accurate stent localization is a key factor impacting the postoperative success of patients undergoing PCI. However, the accurate localization of some lesions, especially ostial lesions, is very difficult to achieve, because they are often complicated by bobbing or to-and-fro movement of the stent during cardiac contractions.

METHODS

We report a novel technique of precise ostial/non-ostial stenting based on the buddy balloon anchor stent (BBAS) technique. Between May 2014 and July 2017, 47 patients with significant ostial/non-ostial coronary stenosis that required accurate stenting were included in this study. Of them, 23 patients were treated using the conventional method and the remaining 24 patients were treated using (BBAS) technique. Evaluation was then performed using intravascular ultrasound (IVUS) in the procedural, or coronary computed tomography angiography (CCTA) in the follow up.

RESULTS

Using the BBAS technique, the procedural success was achieved in all 24 (100%) cases. IVUS was performed in seven patients (29.17%) and no procedural complications occurred. All six failed cases that occurred among patients with right coronary artery and left anterior descending artery ostial stenosis treated using the conventional method, the lesions were subsequently successfully re-stented using the BBAS technique. After a follow-up of 3-36 months, CCTA was performed in 11 patients (45.83%), all the stents were in the accurate position. There were no major cardiovascular events of death, myocardial infarction, or target lesion revascularization.

CONCLUSION

BBAS is a simple, highly successful and safe technique for accurate stenting of difficult ostial/nonostial coronary stenosis lesions.