Carbon fluxes and water-use efficiency in a Pinus tabuliformis plantation in Northeast China and their relationship to drought.

The impact of extreme weather events on carbon fluxes and water-use efficiency (WUE) in revegetated areas under water-limited conditions is poorly understood. We analyzed changes in carbon fluxes and WUE over three years of eddy-covariance measurements in a Pinus tabuliformis plantation in Northeast China to investigate carbon fluxes and WUE responses to drought events at different time scales. Mean annual net ecosystem exchange (NEE), gross primary production (GPP), and ecosystem respiration (Re) were -368.48, 1042.42, and 673.94 g C m-2, respectively. Drought events increased NEE, as GPP was more sensitive to water stress than Re at different growing stages. Mean annual WUE was 2.46 g C kg-1 H2O, and plant phenology played a key role in WUE responses to drought. Water stress had negative and positive effects on daily WUE at the early and late growing stages, respectively, and daily WUE was generally insensitive to drought at the mid growing stage. A lagged effect existed in the carbon fluxes and WUE dynamics after drought events at various time scales. Water stress at the early growing stage was more important than that at other growing stages on annual carbon sequestration and WUE, as it dominated canopy growth in the current year. The annual mean normalized difference vegetation index controlled interannual variations in carbon fluxes and WUE in the plantation. Our findings contribute to the prediction of possible changes in carbon and water fluxes under climate warming in the afforested areas of Northeast China.

Relationship between negative air ion and PM2.5 in Quercus variabilis under natural conditions.

In recent years, PM2.5 pollution has become a most important source of air pollution. Prolonged exposure to high PM2.5 concentrations can give rise to severe health issues. Negative air ion (NAI) is an important indicator for measuring air quality, which is collectively known as the 'air vitamin'. However, the intricate and fluctuating meteorological conditions and vegetation types result in numerous uncertainties in the correlation between PM2.5 and NAI. In this study, we collected data on NAI, PM2.5, and meteorological elements through positioning observation during the period of June to September in 2019 and 2020 under the condition of relatively constant leaf area in Quercus variabilis forest, a typical forest in warm temperate zones. We investigated the spatiotemporal variation of PM2.5 and NAI under consistent meteorological conditions, established the correlation between PM2.5 and NAI, and explicated the impact mechanism of PM2.5 on NAI in natural conditions. The results showed that NAI decreased exponentially with the increases in natural PM2.5, with a significant negative correlation (y=1148.79x-0.123). The decrease rates of NAI in PM2.5 concentrations of 0-20, 20-40, 40-80, 80-100 and 100-120 µg·m-3 were 40.1%, 36.2%, 9.4%, 2.4%, 5.1% and 6.8%, respectively. Results of the sensitivity analysis showed that the PM2.5 concentration range of 0-40 µg·m-3 was the sensitive range that affected NAI. Our findings could provide a scientific basis for better understanding the response mechanisms of NAI to environmental factors.

[Responses of tree growth and intrinsic water-use efficiency of Robinia pseudoacacia to climate factors]. / åˆºæ§ç”Ÿé•¿å’Œå† åœ¨æ°´åˆ†åˆ©ç”¨æ•ˆçŽ‡å¯¹æ°”å€™å› å­çš„å“åº”.

We investigated tree growth in Robinia pseudoacacia plantations at Ansai in Shaanxi Province and at Ji-xian in Shanxi Province by comparing the tree-ring width, basal area increase (BAI), δ13C value, intrinsic water-use efficiency (iWUE), and stomatal regulation. We quantified the responses of tree growth and iWUE to climatic factors at each site. The tree-ring width at Ansai and Jixian decreased with stand age, whereas the BAI at Ansai increased, and that at Jixian decreased after the BAI peaked. The δ13C value and iWUE of trees at Jixian were higher than those at Ansai. The iWUE of trees at both sites was similar to the constant intercellular CO2 concentration/atmospheric CO2 concentration (Ci/Ca) scenario, indicating that the Ci of trees was elevated with increasing Ca, while the stomata remained open. The BAI at Ansai was significantly positively correlated with highest temperature in May, relative humidity in June, precipitation in August, relative humidity in September, and standardized precipitation evapotranspiration index (SPEI) in September and October of current year, but negatively correlated with temperature in June. The BAI at Jixian was significantly positively correlated with SPEI in June and July, and lowest temperature in October of current year. The iWUE of trees at Ansai was significantly positively correlated with relative humidity and precipitation in June of the current year, but negatively correlated with minimum temperature in May, relative humidity in June, and temperature and maximum temperature in July of current year. A significant positive correlation between iWUE of trees at Jixian and lowest temperature in June of current year was detected. At the annual scale, the BAI of trees at Ansai was positively correlated with precipitation and SPEI, but no significant relationship was observed for trees at Jixian. However, the iWUE of trees at both sites was significantly affected by precipitation. Path analysis showed that SPEI and minimum temperature had a direct effect on BAI and iWUE of trees at Ansai, whereas precipitation and average temperature indirectly affected BAI and iWUE through SPEI. The highest temperature had a direct effect on tree growth at Jixian, whereas precipitation, minimum temperature, and average temperature had direct effects on iWUE. These results suggested that SPEI was the main climatic factor that affected the growth of R. pseudoacacia, while Ci was an important physiological factor. Our results could provide reference for the protection and management of R. pseudoacacia plantations under climate change.

Administration of Valproic Acid Improves the Survival of Patients with Glioma Treated with Postoperative Radiotherapy.

OBJECTIVE: The aim of this study was to investigate the impact of valproic acid (VPA) on survival and prognosis of patients with glioma who underwent postoperative radiotherapy. METHODS: We obtained the case data with brain glioma who underwent postoperative radiotherapy from January 2012 to December 2019. This cohort was heterogeneous. We conducted single-factor analysis and multiple-factors analysis of the basic features, pathological classification, therapies of all 185 patients using Kaplan-Meier survival curve, log-rank survival significance test, and Cox regression analysis model. RESULTS: By the end of the last follow-up, 94 patients had died and 96 had recurred in all 185 cases. The median follow-up time of this study was 47 months. The median overall survival (OS) and progression-free survival (PFS) times were 34 and 27 months, respectively. The 1-, 3-, and 5-year OS rates were 86.49%, 48.11%, and 14.60%, respectively. The 1-, 3-, and 5-year PFS rates were 80.00%, 43.78%, and 12.97%, respectively. Univariate analysis revealed that age, pathological grade, and VPA administration were all associated with patients' prognosis (p < 0.05). A Cox multivariate analysis revealed that being 47 years or older, having a high pathological grade (WHO grades III and IV), and not taking VPA were all adverse prognostic factors for OS and PFS in patients with glioma. CONCLUSION: Age, pathological grade, and VPA administration are the influencing factors for the prognosis of glioma patients with postoperative radiotherapy. Patients with glioma who received VPA had a more favorable prognosis and a lower recurrence rate.

Carbon exchange characteristics and their environmental effects in the northern forest ecosystem of the Greater Khingan Mountains in China.

Measurement and analysis of CO2 concentration at the ecosystem scale is the basis for studying ecosystem feedback to global climate change, and it is particularly useful for understanding the processes and mechanisms of ecosystem C exchange. Through observation of CO2 concentration at different heights, this study examined whether a CO2 lake phenomenon exists in the Larix gmelinii ecosystem of the Greater Khingan Mountains (China), and how it might be changed and what might represent its driving factors if such a phenomenon were found to exist. Plants and soils were sampled regularly to determine δ13C and to quantify the proportion of C released by each component of the ecosystem. The main path of C release and the main source of CO2 lake formation were investigated. Statistical analysis revealed that a CO2 lake phenomenon does exist in the L. gmelinii ecosystem. Comparative analysis showed that on the daily scale, when the ecosystem was a C source, the CO2 lake phenomenon often occurred. On the scale of the growing season, the strongest CO2 lake was accompanied by emergence of the peak respiratory flux. Stepwise regression analysis showed that environmental factors could explain 74.87% of the CO2 lake phenomenon. The occurrence and strength of the CO2 lakes were found to mainly respond to changes in temperature. Linear model analysis revealed that the rate of C release from autotrophic respiration in the forest was 51.18%; the rate of C release from heterotrophic respiration during litter decomposition was 51.78%. Therefore, the C release of the L. gmelinii ecosystem is mainly from autotrophic respiration. The CO2 released during decomposition of litter represented the main source for the formation of CO2 lakes. The CO2 lake effect has substantial impact on the net C flux and plays an important role in the C source/sink effect of the ecosystem.

[Growth response to climatic factors and drought events in Quercus variabilis trees of different diameter classes at south aspect of Taihang Mountains, China]. / å¤ªè¡Œå±±å—éº“ä¸åŒå¾„çº§æ “çš®æ Žç”Ÿé•¿å¯¹æ°”å€™è¦ç´ åŠå¹²æ—±äº‹ä»¶çš„å“åº”.

To explore the effects of diameter class on the climate-growth relationship of trees, the width chronologies of ringwood, earlywood, and latewood of Quercus variabilis were established in the low altitude area of the south aspect of the Taihang Mountains. We estimated the sensitivity of radial growth of two diameter classes of Q. variabilis plantation to climate. The effects of drought events on Q. variabilis plantation was quantified by superimposed time analysis. Under climate change, we aimed to provide reference data for sustainable management of Q. variabilis. Our results showed that the mean sensitivity of ringwood and latewood of large diameter classes were higher than small diameter classes. The mean sensitivities of earlywood of small diameter classes were higher than large diameter classes. The latewood was the most sensitive component of tree-ring. The responses of the standard chronological indices of two diameter classes to climate factors were similar. The growth of ringwood and latewood of small diameter classes were more sensitive to the climatic factors from June to August. The earlywood was more sensitive to the climatic factors before the growing season (from January to February). Furthermore, the earlywood of large diameter classes was more sensitive to the climatic factors of the last year, with a stronger hysteresis effect. It suggested that Q. variabilis was sensitive to drought. The radial growth of Q. variabilis of ringwood and latewood in drought year was significantly lower than that of last year. The reduction of Q. variabilis with large diameters was higher than that of small diameters, but with higher growth recovery degree after drought.

Long-Term Effects of Climate and Competition on Radial Growth, Recovery, and Resistance in Mongolian Pines.

Understanding the response of tree growth and drought vulnerability to climate and competition is critical for managing plantation forests. We analyzed the growth of Mongolian pines in six forests planted by the Three-North Shelter Forest Program with tree-ring data and stand structures. A retroactive reconstruction method was used to depict the growth-competition relationships of Mongolian pines during the growth period and their climatic responses under different competition levels. Drought vulnerability was analyzed by measuring the basal area increment (BAI) of different competition indices (CIs). In young trees, differences in BAIs in stands with different CIs were not statistically significant. After 15-20 years, medium- and high-CI stands had significantly lower tree-ring widths (TWs) and BAIs than the low-CI stands (p < 0.05). The standardized precipitation evapotranspiration index (SPEI), precipitation, relative humidity, and vapor pressure deficit were major factors affecting tree growth. On a regional scale, climate outweighed competition in determining radial growth. The relative contribution of climatic factors increased with the gap in SPEI between plantation sites and the native range, while the reverse pattern of the competition-growth relationship was observed. Drought reduced TWs and BAIs at all sites. Stands of different CIs exhibited similar resistance, but, compared with low-CI stands, high- and medium-CI stands had significantly lower recovery, resilience, and relative resilience, indicating they were more susceptible to drought stresses. Modeled CI was significantly negatively related to resistance, resilience, and relative resilience, indicating a density-dependence of tree response to drought. After exposure to multiple sequential drought events, the relative resilience of high-CI stands decreased to almost zero; this failure to fully recover to pre-drought growth rates suggests increased mortality in the future. In contrast, low-CI stands are more likely to survive in hotter, more arid climates. These results provide a better understanding of the roles of competition and climate on the growth of Mongolian pines and offer a new perspective for investigating the density-dependent recovery and resilience of these forests.

GDNF Promotes Survival and Therapeutic Efficacy of Human Adipose-Derived Mesenchymal Stem Cells in a Mouse Model of Parkinson's Disease.

Mesenchymal stem cell (MSC)-based regenerative therapy is regarded as a promising strategy for the treatment of Parkinson's disease (PD). However, MSC components may exhibit poor intracranial survivability, particularly in the later stages following cell transplantation, limiting their potential curative effect and also clinical applications. Glial cell line-derived neurotrophic factor (GDNF), which encompasses a variety of transforming growth factor beta super family members, has been reported to enhance motor function and exert neuroprotective effects. However, no previous studies have investigated the effects of GDNF on human primary adipose-derived MSCs (hAMSCs), despite its potential for enhancing stem cell survival and promoting therapeutic efficacy in the treatment of PD. In the present study, we proposed a novel approach for enhancing the proliferative capacity and improving the efficacy of hAMSC treatment. Pre-exposure of engineered hAMSCs to GDNF enhanced the proliferation and differentiation of these stem cells in vitro. In addition, in 6-hydroxydopamine-lesioned mice, a common PD model, intracranial injection of hAMSCs-GDNF was associated with greater performance on behavioral tests, larger graft volumes 5 weeks after transplantation, and higher levels of Nestin, glial fibrillary acidic protein, and Tuj-1 differentiation than those treated with hAMSCs-Vector. Following transplantation of hAMSCs-GDNF into the striatum of lesioned models, we observed significant increases in tyrosine hydroxylase- and NeuN-positive staining. These findings highlight the therapeutic potential of hAMSCs-GDNF for patients with PD, as well as an efficient method for promoting therapeutic efficacy of these delivery vehicles.

[Differences in atmospheric CO2 concentration and δ13C value between green spaces and its adjacent roads as well as the influencing factors in Beijing, China.] / 北京城市绿地与周边道路空气CO2浓度和δ13Cå€¼çš„å·®å¼‚åŠå½±å“å› ç´ .

Near-surface atmospheric CO2 concentration and δ13C value in four greenspaces and on their adjacent roads in Beijing were measured by off-axis integrated cavity output spectroscopy to analyze the influence of urban greenspace on spatial distribution of near-surface atmospheric CO2. The results showed that atmospheric CO2 concentration and δ13C value varied substantially both temporally and spatially. The highest CO2 concentration was found in the urban area, followed by the suburbs, and the lowest CO2 concentration was in the outer suburbs. There was a clear near-surface atmospheric CO2 dome, but a reverse pattern for δ13C value. During the non-growing season, the ΔCO2 and Δ13C between greenspace and adjacent roads were low. The differences among the four experimental sites were not significant. In the growing season, the ΔCO2 and Δ13C at the BLA4th RR (Beijing Institute of Landscape Architecture and 4th Ring Road) and BOP5th RR (Beijing Olympic Forest Park and 5th Ring Road) in urban areas were significantly higher than those at DPSR (Daoxianghu Park and Sujiatuo Road) and MTGMR (Mentougou forest experimental station and an adjacent road) in the suburbs. During the growing and non-growing seasons, CO2 concentration of all examined sites was significantly positively related with the traffic volume, indicating that traffic volume was an important factor affecting the spatial distribution of CO2. The δ13C value was significantly negatively related with traffic volume during non-growing season, but no significant relationship was found during the growing season. The ΔCO2 concentration between the four green-spaces and their adjacent roads were significantly negatively related with leaf area index (LAI). The Δ13C value were significantly logarithmically related to LAI. Results from stepwise regression showed that solar radiation, temperature, and LAI significantly affected ΔCO2 in urban areas and suburbs during the growing season, and that temperature and solar radiation were the major driving factors for Δ13C. During the growing season, plants in the greenspaces assimilated CO2 via photosynthesis and thus reduced the near-surface atmospheric CO2 concentration. Our results indicate that green-spaces play a positive role in improving ecological environment in urban areas.

Exploiting tumor-intrinsic signals to induce mesenchymal stem cell-mediated suicide gene therapy to fight malignant glioma.

BACKGROUND: Human mesenchymal stem cell (MSC)-based tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene delivery is regarded as an effective treatment for glioblastoma (GBM). However, adverse-free target site homing of the delivery vehicles to the tumor microsatellite nests is challenging, leading to erroneously sustained released of this suicide protein into the normal brain parenchyma; therefore, limiting off-target cytotoxicity and controlled expression of the suicide inductor is a prerequisite for the safe use of therapeutic stem cells. METHODS: Utilizing the intrinsic expression profile of GBM and its elevated expression of TGF-ß relative to normal brain tissue, we sought to engineer human adipose-derived MSCs (hAMSC-SBE4-TRAIL) which augment the expression of TRAIL under the trigger of TGF-ß signaling. We validated our therapeutic technology in a series of functional in vitro and in vivo assays using primary patient-derived GBM models. RESULTS: Our current findings show that these biologic delivery vehicles have high tumor tropism efficacy and expression TRAIL gene under the trigger of TGF-ß-secreting GBMs, as well as avoid unspecific TRAIL secretion into normal brain tissue. hAMSC-SBE4-TRAIL inhibited the proliferation and induced apoptosis in experimental GBMs both in vitro and in vivo. In addition, our improved platform of engineered MSCs significantly decreased the tumor volume and prolonged survival time in a murine model of GBM. CONCLUSIONS: Our results on the controlled release of suicide inductor TRAIL by exploiting an endogenous tumor signaling pathway demonstrate a significant improvement for the clinical utility of stem cell-mediated gene delivery to treat brain cancers. Harvesting immune-compatible MSCs from patients' fat by minimally invasive procedures further highlights the clinical potential of this approach in the vision of applicability in a personalized manner. The hAMSC-SBE4-TRAIL exhibit great curative efficacy and are a promising cell-based treatment option for GBM to be validated in clinical exploration.

Clinical, radiological, and histological features and treatment outcomes of supratentorial extraventricular ependymoma: 14 cases from a single center.

OBJECTIVE Reports on supratentorial extraventricular ependymoma (STE) are relatively rare. The object of this study was to analyze the clinical, radiological, and histological features and treatment outcomes of 14 patients with STE. METHODS Overall, 227 patients with ependymoma underwent surgical treatment in the authors' department between January 2010 and June 2015; 14 of these patients had STE. Data on clinical presentation, radiological studies, histopathological findings, surgical strategies, and treatment outcomes in these 14 cases were retrospectively analyzed. RESULTS The patients consisted of 6 women and 8 men (sex ratio 0.75). Mean age at diagnosis was 24.5 ± 13.5 years (range 3-48 years). Tumors were predominantly located in the frontal and temporal lobes (5 and 4 cases, respectively). Typical radiological features were mild to moderate heterogeneous tumor enhancements on contrast-enhanced MRI. Other radiological features included well-circumscribed, "popcorn" enhancement and no distinct adjoining brain edema. Gross-total resection was achieved in 12 patients, while subtotal removal was performed in 2. Radiotherapy was administered in 7 patients after surgery. Seven tumors were classified as WHO Grade II and the other 7 were verified as WHO Grade III. The mean follow-up period was 22.6 months (range 8-39 months). There were 3 patients with recurrence, and 2 of these patients died. CONCLUSIONS Supratentorial extraventricular ependymoma has atypical clinical presentations, various radiological features, and heterogeneous histological forms; therefore, definitive diagnosis can be difficult. Anaplastic STE shows malignant biological behavior, a higher recurrence rate, and a relatively poor prognosis. Gross-total resection with or without postoperative radiotherapy is currently the optimal treatment for STE.

Clinical analysis and surgical treatment of trigeminal neuralgia caused by vertebrobasilar dolichoectasia: A retrospective study.

BACKGROUND: Trigeminal neuralgia (TN) caused by vertebrobasilar dolichoectasia (VBD) is rare and needs further exploration. The purpose of this study is to investigate the clinical features and surgical treatment of TN caused by VBD. METHODS: 15 patients with TN caused by VBD were included in our study. The patient data regarding clinical characteristics, neuroimaging presentations, intraoperative findings and treatment outcomes were analyzed retrospectively. Moreover, the previous relevant literature was reviewed simultaneously. Simple MVD was performed in 13 cases and MVD plus trigeminal nerve selective partial posterior rhizotomy (SPPR) was conducted in 2 patients. RESULTS: Of all patients, 7 cases were female and 8 were male. The average age at operation was 60.8 years old (range, 35yrs-75yrs). 13 patients suffered from hypertension and 7 had a history of stoke. The extended and ectatic vetebrobasilar artery (VBA) was preliminarily identified in preoperative imaging presentations and finally confirmed during surgical procedure. The facial neuralgia disappeared immediately after surgery in all patients. All patients were relieved of pain (BNI score I) with an average of 29.8 months follow-up. CONCLUSIONS: Our results suggest that simple MVD is effective for TN caused by VBD. MVD plus SPPR can be cautiously performed if patient has advanced age and is susceptible to numbness.

Histopathological features of middle cerebral artery and superficial temporal artery from patients with moyamoya disease and enlightenments on clinical treatment.

The histopathological features of the middle cerebral artery (MCA) and superficial temporal artery (STA) from moyamoya disease (MMD) and their relationships with gender, age, angiography stage were explored. The causes and the clinical significance of vasculopathy of STA were also discussed. The clinical data and specimens of MCA and STA from 30 MMD patients were collected. Twelve samples of MCA and STA from non-MMD patients served as control group. Histopathological examination was then performed by measuring the thickness of intima and media, and statistical analysis was conducted. The MCA and STA specimens from MMD group had apparently thicker intima and thinner media than those from the control group. There was no significant pathological difference between the hemorrhage group and non-hemorrhage group, and between the males and females in MMD patients. Neither the age nor the digital subtraction angiography (DSA) stage was correlated with the thickness of intima in MCA and STA. MMD is a systemic vascular disease involving both intracranial and extracranial vessels. Preoperative external carotid arteriography, especially super-selective arteriography of the STA, benefits the selection of donor vessel.

Significance of cyclooxygenase-2 elevation in middle cerebral artery for patients with hemorrhagic moyamoya disease.

The etiology and pathogenesis of moyamoya disease (MMD) remain elusive. Some inflammatory proteins, such as cyclooxygenase (COX)-2, are believed to be implicated in the development of MMD. So far, the relationship between COX-2 and MMD is poorly understood and reports on the intracranial vessels of MMD patients are scanty. In this study, tiny pieces of middle cerebral artery (MCA) and superficial temporal artery (STA) from 13 MMD patients were surgically harvested. The MCA and STA samples from 5 control patients were also collected by using the same technique. The expression of COX-2 was immunohistochemically detected and the average absorbance (A) of positively-stained areas was measured. High-level COX-2 expression was found in all layers of the MCA samples from all 5 hemorrhagic MMD patients, while positive but weak expression of COX-2 was observed only in the endothelial layer of the MCA samples from most ischemic MMD patients (6/8, 75%). The average A values of COX-2 in the hemorrhagic MMD patients were substantially higher than those in their ischemic counterparts (t=4.632, P=0.001). There was no significant difference in the COX-2 expression among the "gender" groups, or "radiographic grade" groups, or "lesion location" groups (P>0.05 for all). The COX-2 expression was detected neither in the MCA samples from the controls nor in all STA specimens. Our results suggested that COX-2 was up-regulated in the MCA of MMD patients, especially in hemorrhagic MMD patients. We are led to speculate that COX-2 may be involved in the pathogenesis of MMD and even contribute to the hemorrhagic stroke of MMD patients.

Cyclooxygenase-2 and Prostaglandin E2 are Associated with Middle Cerebral Artery Occlusion and Hemorrhage in Patients with Moyamoya Disease.

Some inflammatory proteins, such as cyclooxygenase (COX)-2 and prostaglandin (PG) E2 are hypothesized to be implicated in the development of moyamoya disease (MMD). However, the functional roles of COX-2/PGE2 in the pathogenesis of MMD remain elusive. In this study, tiny pieces of middle cerebral artery (MCA) and superficial temporal artery (STA) were surgically harvested from 18 adult MMD patients and 5 surgical control patients. The expression levels of COX-2 and microsomal prostaglandin E2 synthase-1 (mPGES-1) in the vascular walls were immunohistochemically detected. With additional 10 healthy controls, the plasma levels of PGE2 were also measured by enzyme-linked immunosorbent assay (ELISA). Obvious intimal thickening was observed in both STA and MCA of MMD patients, but not in the controls. However, the MCA had a thicker intima than the STA (P < 0.01). Although plasma concentrations of PGE2 had no differences among the MMD patients, surgical controls and healthy controls, MCA of most MMD patients (15/18, 83.3%) were stained positively for COX-2 and all patients for mPGES-1. Staining of both COX-2 and mPGES-1 was more abundant in the MCA of hemorrhagic patients than those in their ischemic counterparts (P = 0.001 and 0.029, respectively). The expression levels of COX-2 were positively correlated with those of mPGES-1 (r = 0.647, P = 0.004). Positive COX-2 and mPGES-1 expressions were detected neither in the MCA samples from the surgical controls nor in all STA specimens. Our findings indicate that COX-2/PGE2 may be associated with the MCA occlusion and the hemorrhagic stroke in patients with MMD.

[Variations of CO2 concentration and δ13C and influencing factors of Quercus variabilis plantation in low hilly area of North China].

The off-axis integrated cavity output spectroscopy technique was used to measure air CO2 concentration and stable carbon isotope ratio (δ13C) above (11 m) and at the bottom (6 m) of canopy of a Quercus variabilis plantation in a low hilly area of North China. The variations of CO2 concentration and δ13C value in Q. variabilis plantation canopy and the influencing factors were analyzed at hourly timescale. The results showed that diurnal variation in the CO2 concentration had a trend, while there was no obvious similar tendency in the diurnal change of δ13C value. Daytime atmosphere stability frequency during the experiment time was 70.2%. With the combined effects of photosynthesis and turbulent in the canopy, CO2 concentration at the bottom of canopy was 1.70 µmol · mol(-1) higher than that above the canopy, while the δ13C value was 0.81 per thousand lower than that above the canopy. Atmosphere stability frequency was 76.2% at night. The CO2 from leaf was not easy to move because of weak turbulent. Thus, CO2 concentration at the bottom of canopy was 1.24 µmol · mol(-1) higher than that above canopy, while the δ13C value was 0.58 per thousand lower than that above canopy. The difference of CO2 concentration between above and at the bottom of the canopy was strongly correlated with their δ13C difference both in daytime and at nighttime. Stepwise regression analysis indicated that solar radiation and relative humidity in daytime were the main environmental factors causing CO2 concentration and δ13C difference between above and at the bottom of the canopy, whereas at nighttime temperature was a key environmental factor influencing δ13C value. The above environmental factors strongly influenced CO2 concentration and δ13C value in air above and at the bottom of Q. variabilis plantation canopy by increasing or decreasing photosynthesis and respiration.

Treatment strategies for huge central neurocytomas.

Central neurocytomas (CNs), initially asymptomatic, sometimes become huge before detection. We described and analyzed the clinical, radiological, operational and outcome data of 13 cases of huge intraventricular CNs, and discussed the treatment strategies in this study. All huge CNs (n=13) in our study were located in bilateral lateral ventricle with diameter ≥5.0 cm and had a broad-based attachment to at least one side of the ventricle wall. All patients received craniotomy to remove the tumor through transcallosal or transcortical approach and CNs were of typical histologic and immunohistochemical features. Adjuvant therapies including conventional radiation therapy (RT) or gamma knife radiosurgery (GKRS) were also performed postoperatively. Transcallosal and transcortical approaches were used in 8 and 5 patients, respectively. Two patients died within one month after operation and 3 patients with gross total resection (GTR) were additionally given a decompressive craniectomy (DC) and/or ventriculoperitoneal shunt (VPS) as the salvage therapy. Six patients received GTR(+RT) and 7 patients received subtotal resection (STR)(+GKRS). Eight patients suffered serious complications such as hydrocephalus, paralysis and seizure after operation, and patients who underwent GTR showed worse functional outcome [less Karnofsky performance scale (KPS) scores] than those having STR(+GKRS) during the follow-up period. The clinical outcome of huge CNs seemed not to be favorable as that described in previous reports. Surgical resection for huge CNs should be meticulously considered to guarantee the maximum safety. Better results were achieved in STR(+GKRS) compared with GTR(+RT) for huge CNs, suggesting that STR(+GKRS) may be a better treatment choice. The recurrent or residual tumor can be treated with GKRS effectively.

[Seasonal characteristics of δD and δ18O in precipitation and its water vapor sources in the Xiaolangdi Reservoir area of Yellow River, China].

The seasonal characteristics of δD and δ¹8O in precipitation and the influence factors were studied in the Xiaolangdi Reservoir area at the eastern monsoon region of China. The precipitation samples and the corresponding meteorological data were collected between April and October from the year 2011 to 2014. The local meteoric water lines (LMWL) of different seasons were established, and the water vapor sources in different seasons were investigated. The results showed that the δD and δ¹8O in precipitation exhibited an extremely wide range and a distinct seasonal variation, and they were enriched in the spring, and depleted in the fall. The δD and δ¹8O values showed negative correlations with the amount of precipitation from April to October and the fall, respectively. The δD values and the mean air temperature showed a negative correlation from April to October, but showed no correlation in seasonal precipitation. Both the slopes of LMWL and excess deuterium (d values) of precipitation were the smallest in the summer, and the largest in the fall. The results of air mass back trajectories of seasonal precipitation using the HYSPLIT model indicated a dominant effect of southeast and southwest maritime monsoon air masses in the summer and the co-influence of continental and oceanic monsoons air masses in the spring and fall in the study area.

[Differences and sources of CO2 concentration, carbon and oxygen stable isotope composition between inside and outside of a green space system and influencing factors in an urban area].

The off-axis integrated cavity output spectroscopy technique was used to measure air CO2 concentration, stable carbon (δ13C) and oxygen (δ18C) isotope ratios on the Fourth Ring Road (FRR) and in the green space system of Beijing Institute of Landscape Architecture (BILA) in summer and winter seasons. The variations of CO2 concentration, δ13C value, δ18C value and the differences of them between the FRR and the BILA, which were correlated with traffic volume and meteorological factors, were analyzed at half-hour timescale. The results showed that traffic volume on the FRR was large both in summer and winter with obvious morning and evening rush hours, and more than 150 thousands vehicles were observed everyday during the observation periods. Diurnal variation of the CO2 concentration showed a two-peak curve both on the FRR and in the green space system of the BILA. In contrast, diurnal variation of δ13C value was a two-trough curve while diurnal variation of δ18O value was a single-trough curve. The differences of CO2 concentration, δ13C value and δ18O value between the FRR and the green space system of BILA in summer were greater than those in winter. The carbon isotope partitioning results showed that in summer vehicle exhaust contributed 64.9% to total atmospheric CO2 of the FRR during measurement time, while heterotrophic respiration contributed 56.3% to total atmospheric CO2 of the green space system in BILA. However, in winter atmospheric CO2 from both the FRR and green space system mostly came from vehicle exhaust. Stepwise regression analysis indicated that differences of CO2 concentration between the FRR and green space system were significantly related to vehicle volume and solar radiation at half-hour timescale, while solar radiation and relative humidity were the main meteorological factors causing δ13 and δ18O differences between the FRR and green space system. Plants in the green space system strongly assimilated CO2 from fossil fuel burning by photosynthesis to maintain carbon and oxygen balance of urban area in the growing season, which played an important role in improving urban ecological environment.

A comparative study of intraventricular central neurocytomas and extraventricular neurocytomas.

Similar histology and clinical behavior of both intraventricular central neurocytomas (CNs) and extraventricular neurocytomas (EVNs) may argue against the idea that EVNs were the distinct entity to distinguish from CNs in the 2007 World Health Organization classification. To explore respective characteristics and compare similarities and differences in CNs and EVNs, relevant clinical, radiological, operative and pathological data of 49 patients (35 CNs and 14 EVNs) in the Department of Neurosurgery at our hospital from 2005 to 2012 was reviewed and some comparisons between CNs and EVNs were conducted. The factors affecting posttreatment recurrence of CNs and EVNs were assessed by Cox regression analysis. In comparison, CNs showed a more typical clinical manifestation, and radiological and histopathological features, while EVNs demonstrated more malignant biological behavior, with higher MIB-1 index (p = 0.006), higher rate of atypia (p = 0.042), higher recurrence rate (p = 0.028), and shorter time to recurrence (p = 0.049). Subtotal resection was associated with higher rates of recurrence in both CNs (hazard ratio [HR] 6.16, p = 0.046) and EVNs (HR 5.26, p = 0.045), and atypia was also associated with a higher recurrence rate in CNs (HR 5.03, p = 0.042). CNs were thus easier to diagnose than EVNs, with typical clinical, radiological, and histopathological features, while the latter were more likely to show malignant biological behavior associated with atypia and recurrence. Total surgical resection is the optimal treatment choice for both CNs and EVNs, and patients with either CN or EVN with typical and/or totally resected lesions showed favorable clinical outcomes.