Water content estimation of conifer needles using leaf-level hyperspectral data.

Water is a crucial component for plant growth and survival. Accurately estimating and simulating plant water content can help us promptly monitor the physiological status and stress response of vegetation. In this study, we constructed water loss curves for three types of conifers with morphologically different needles, then evaluated the applicability of 12 commonly used water indices, and finally explored leaf water content estimation from hyperspectral data for needles with various morphology. The results showed that the rate of water loss of Olgan larch is approximately 8 times higher than that of Chinese fir pine and 21 times that of Korean pine. The reflectance changes were most significant in the near infrared region (NIR, 780-1300 nm) and the short-wave infrared region (SWIR, 1300-2500 nm). The water sensitive bands for conifer needles were mainly concentrated in the SWIR region. The water indices were suitable for estimating the water content of a single type of conifer needles. The partial least squares regression (PLSR) model is effective for the water content estimation of all three morphologies of conifer needles, demonstrating that the hyperspectral PLSR model is a promising tool for estimating needles water content.

Lab-on-fiber: laser-induced micro-cavity for a relative humidity measurement.

The lab-on-fiber design philosophy is the foundation for creating high-performance integrated fiber sensors. Hence, this Letter proposes an ultra-compact Fabry-Perot interferometer (FPI) based on a laser-induced micro-cavity (LIMC-FPI) on a fiber end for measuring relative humidity. To our knowledge, this novel approach, named the fiber-end photopolymerization (FEP) technique, is applied to create a micro-cavity. Specifically, a pair of humidity-sensitive polymer pillars and a resin end cap obtained by FEP are integrated to generate the cavity. As the ambient humidity changes, the pillars lengthen or shorten, resulting in the spectral evolution of the LIMC-FPI. A typical humidity sensitivity of 0.18 nm/%RH is obtained experimentally. For monitoring the human breathing process, the LIMC-FPI is responsive in the breathing frequency range of 0.2 to 0.5 Hz, allowing a response and recovery time of less than 0.388 s and 1.171 s, respectively. This work introduces a fresh and cost-effective approach for developing lab-on-fiber concept-based sensors.

Highly-sensitive temperature sensor based on photopolymerized-waveguide embedded Mach-Zehnder interferometer.

Biology, medicine, and chemistry all rely heavily on highly sensitive optical fiber temperature sensors. To the best of our knowledge, this research introduces a unique design framework for high-performance fiber temperature sensors that helps eliminate the all-fiber interferometers' sensitivity bottleneck. A section of photopolymerized waveguide is embedded in a typical Mach-Zehnder interferomenter framework with multimode fiber-single mode fiber-multimode fiber (MSM) structure. The thermal-optical coefficient (TOC) of the photopolymerized waveguide core, which is created via the fiber-end lithography technique, differs dramatically from that of the resin cladding. Due to the considerable TOC difference, the phase difference between the interfering beams significantly increases as the temperature changes. The fundamental variables affecting temperature sensitivity are conceptually explored and experimentally verified. The suggested device achieves a typical temperature sensitivity of 1.15 nm/ ∘C in the range of 30-100 ∘C, which is about 10 times as high as that of the all-fiber MSM sensors. The suggested designing framework offers a fresh thought for creating high-performing fiber optic temperature sensors.

Temporal and spatial variations and influencing factors of gross primary productivity in Changbai Mountain Nature Reserve, China.

Changbai Mountain Nature Reserve (CNR) is a typical temperate forest ecosystem, and gross primary production (GPP) of which is closely related to topography and climate change. Research on the spatio-temporal variations and influencing factors of GPP in the CNR is of great significance for assessing growth status of vegetation and the quality of ecological environment. We calculated GPP in CNR using the vegetation photosynthesis model (VPM), and analyzed the influences of slope, altitude, temperature, precipitation, and total radiation. The results showed that the range of annual average GPP in CNR was 63-1706 g C·m-2·a-1 from 2000 to 2020 and that GPP decreased with the increases of altitude. Temperature played the most important role in driving the spatial varia-tion of GPP, with a significant positive correlation with GPP. During the study period, the overall annual GPP showed a significant increase trend in CNR, with an average annual increase of 13 g C·m-2·a-1. The areas with increase of annual GPP accounted for 79.9% of the total area, and the area proportion of annual GPP increase differed in each plant functional type. Annual precipitation was significantly negatively correlated with GPP in 43.2% of CNR, while annual mean temperature and annual total radiation were significantly positively correlated with GPP in 47.2% and 82.4% of CNR. GPP would increase continuously in CNR under the scenario of future global warming.

Exoskeleton type long-period fiber grating for cross-talk-resistance single-parameter measurement.

This paper proposes a new, to the best of our knowledge, design framework of long-period fiber grating (LPFG) sensors resistant to multi-parameter cross talk. A section of hollow quartz capillary (HQC), which acts as an exoskeleton, is periodically merged with a single-mode fiber (SMF) by the arc-discharge method. The mechanical stress in the SMF is released while the thermal stress is enhanced after a high-temperature fusion process. Under the influence of the elastic-optical effect, the refractive index of the core is periodically modulated along the axial direction to form an exoskeleton long-period fiber grating (Es-LPFG). The unique exoskeleton structure not only induces mode coupling but also enables the proposed device to resist cross talk among the strain, ambient refractive index, and vector bending. The temperature is able to be measured independently with a sensitivity of 74 pm/ ∘C. The novel Es-LPFG is promising in single-parameter sensing, mode-locked lasers, and frequency-locked gain flattening.

Microtopography mediates the climate-growth relationship and growth resilience to drought of Pinus tabulaeformis plantation in the hilly site.

Understanding the factors affecting the growth of plantation forests can reduce the loss of economic and ecological values caused by plantation forest subhealth. Plantation forests are widely distributed in hilly areas with microtopographic features. Microtopography influences climatic factors associated with plant growth, during not only general time but also extreme events like droughts. However, little research has been conducted on the effects of microtopography on the plantation forest growth. In this paper, we selected Pinus tabulaeformis planted in a hilly site, and studied the effect of microtopography on the climate-growth relationship and drought response of a typical plantation in Northeast China using dendroecological methods. We found: 1) Between hill positions, temperature caused a climatic growth difference. Compared to the hilltop, the correlation of annual growth on the hillside with monthly temperature was more negative in July-August and less positive in January-April. 2) Between aspects, precipitation intensities caused a climatic growth difference. Compared to the sunny slope, the correlation of annual growth on the shady slope with monthly total precipitation below 10 mm/day was less positive (May-June) or more negative (March-April and July), while that with monthly total precipitation above 10 mm/day was more positive in most months.3) Drought response varied significantly based on hill position and aspect. There was no significant difference in resistance between hill positions, while recovery and resilience on the hilltop were greater than those on the hillside.Resistance, recovery, and resilience were all lower on the sunny slope than those on the shady slope. Overall, microtopography exists the effects on the growth of plantation forests, both in terms of climate-growth relationships in general climate and in response to drought when extreme events. Meanwhile, the climatic factors that caused the difference in growth of plantation forests between hill positions and aspects differed. The difference in growth between hill positions was caused by temperature, while that between aspects was caused by precipitation intensity. Drought response difference reflected the legacy effect of drought on plantation growth, which could lead to subsequent changes in climate-growth relationships. These findings demonstrate that strengthening the research of forest trees on microtopography is necessary for accurate carbon sink assessment and precise forest management.

Fluorination of Polyethylenimines for Augmentation of Antibacterial Potency via Structural Damage and Potential Dissipation of Bacterial Membranes.

The rise of drug-resistant bacteria (e.g., methicillin-resistant Staphylococcus aureus, MRSA) has continued, making the ″super-bugs″ a formidable threat to global health. Herein, we synthesize a series of fluoroalkylated polyethylenimines (PEI-F) with different grafting degrees of fluoroalkyls via a simple ring-opening reaction and demonstrate for the first time that fluoroalkylated PEIs are able to exert potent antibacterial activity to Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Among the fluoroalkylated polymers, PEI-F3.0 shows the strongest antibacterial activity, with a minimum inhibitory concentration (MIC) of 64 µg mL-1, against both E. coli and S. aureus. More importantly, we find that PEI-F3.0 is able to kill over 99.8% of S. aureus within 1 min, which is extremely desirable for the treatment of acute and severe bacterial infections that require quick disinfection. We also demonstrate that the fluoroalkylated PEIs are able to kill bacteria via structural damage of the outer membrane (OM) and cytoplasmic membrane (CM), potential dissipation of CM, and generation of intracellular reactive oxygen species (ROS). The in vivo antibacterial test suggests that commercial Vaseline blended with 6.25 wt % of PEI-F3.0 (VL/PEI-F3.0) is able to efficaciously eradicate MRSA infection on a bacterial infected wound model and promote the healing procedure of the wound site. Therefore, the fluoroalkylated PEIs provide a promising strategy to cope with the major challenges of drug-resistant infections.

[Water use efficiency and leaf nutrient characteristics of five major tree species in broadleaved Korean pine forest in Changbai Mountains, China]. / 长白山阔叶红松林5ç§ä¸»è¦æ ‘ç§æ°´åˆ†åˆ©ç”¨æ•ˆçŽ‡ä¸Žå¶ç‰‡å »åˆ†ç‰¹å¾.

Water use efficiency (WUE) of five dominant tree species (Pinus koraiensis, Fraxinus mandshurica, Acer mono, Quercus mongolica, and Tilia amurensis) was estimated using the stable carbon isotope method in a broadleaved Korean pine forest in Changbai Mountains. Leaf carbon (C), nitrogen (N), and phosphorus (P) contents were measured to analyze nutrient utilization of the dominant species. The relationship between WUE and leaf nutrient contents was systematically assessed. WUE was different due to the variations of micrometeorological factors at different locations in the canopy. The four broadleaved tree species showed upper layer > middle layer > lower layer, while P. koraiensis showed upper layer > lower layer > middle layer. WUE of evergreen coniferous P. koraiensis was higher than that of two broadleaved species with diffuse-porous wood (T. amurensis and A. mono) and lower than that of two broadleaved species with ring-porous wood (F. mandshurica and Q. mongolica). The compound-leaved species (F. mandshurica) had the highest WUE. The WUE of new leaves was significantly higher than old leaves in P. koraiensis. The carbon content and C/N of the old and new leaves of evergreen coniferous P. koraiensis were significantly higher than those of the other four broadleaved tree species, while nitrogen content and N/P were significantly lower than those of the four broadleaved tree species. P content of old leaves of P. koraiensis was significantly lower than that of the four broadleaved tree species. P content of new leaves of current year was not significantly different from that of the broadleaved tree species. The WUE of five tree species had a poor correlation with leaf C content, but a positive correlation with leaf N content. The WUE of evergreen coniferous and deciduous broadleaved tree species was correlated with leaf P content but in opposite direction.

Autotrophic respiration modulates the carbon isotope composition of soil respiration in a mixed forest.

Carbon isotopic composition of soil respired CO2 (soil δ13CR) has been regarded as a good indicator of the linkages between aboveground processes and soil respiration. However, whether δ13CR of autotrophic or heterotrophic component of soil respiration dominates the temporal variability of total soil δ13CR was rarely examined by previous studies. In this study, carbon isotopic composition of atmospheric CO2 (δ13Cair) and soil δ13CR in control (with roots) and trenched (without roots) plots were measured in a temperated mixed forest. A 13C isotopic profile system and an automated soil respiration system were used for δ 13Cair and soil δ13CR measurements, respectively. We found that soil δ13CR in the control plots changed substantially in the growing season and it was more negative (by ~0.6‰) than that in the trenched plots, while soil δ13CR in the trenched plots showed a minor temporal variability. This suggests that δ13CR from the autotrophic respiration is the key decider of the seasonal variation pattern of the soil δ13CR. Moreover, the seasonal variation of soil δ13CR in the control plots showed a similar pattern with the seasonal variation of δ13Cair. A significant time-lag was found between δ13Cair and soil δ13CR, showing that soil δ13CR generally lagged behind δ13Cair 15 days. This result supports the hypothesis that soil respiration is closely related to carbon assimilation at the leaf-level and also stressed the importance of δ13Cair in shaping soil δ13CR. These findings are highly valuable to develop the process-based models of the carbon cycle of forest ecosystems.

Seawater exposure causes hydraulic damage in dying Sitka-spruce trees.

Sea-level rise is one of the most critical challenges facing coastal ecosystems under climate change. Observations of elevated tree mortality in global coastal forests are increasing, but important knowledge gaps persist concerning the mechanism of salinity stress-induced nonhalophytic tree mortality. We monitored progressive mortality and associated gas exchange and hydraulic shifts in Sitka-spruce (Picea sitchensis) trees located within a salinity gradient under an ecosystem-scale change of seawater exposure in Washington State, USA. Percentage of live foliated crown (PLFC) decreased and tree mortality increased with increasing soil salinity during the study period. A strong reduction in gas exchange and xylem hydraulic conductivity (Ks) occurred during tree death, with an increase in the percentage loss of conductivity (PLC) and turgor loss point (πtlp). Hydraulic and osmotic shifts reflected that hydraulic function declined from seawater exposure, and dying trees were unable to support osmotic adjustment. Constrained gas exchange was strongly related to hydraulic damage at both stem and leaf levels. Significant correlations between foliar sodium (Na+) concentration and gas exchange and key hydraulic parameters (Ks, PLC, and πtlp) suggest that cellular injury related to the toxic effects of ion accumulation impacted the physiology of these dying trees. This study provides evidence of toxic effects on the cellular function that manifests in all aspects of plant functioning, leading to unfavourable osmotic and hydraulic conditions.

[Characteristics of water use efficiency in a succession series of broadleaved Korean pine forests in Changbai Mountain, China.] / 长白山阔叶红松林演替序列水分利用效率特征.

Water use efficiency (WUE) is an objective indicator of plant water use, the research of which is helpful to understand the carbon-water coupling mechanism in terrestrial ecosystems. We investigated WUE of dominant tree species in the succession series of broad-leaved Korean pine forests in Changbai Mountain (middle-aged poplar-birch secondary forest, mature poplar-birch secondary forest, broad-leaved Korean pine forest) by using stable carbon isotope technology. The WUE of three forests under different succession stages decreased in order of broad-leaved Korean pine forest > middle-aged poplar-birch secondary forest > mature poplar-birch secondary forest. In addition, the same tree species had different WUE in different forest stands. The WUE of Populus davidiana and Betula platyphylla in the middle-aged poplar-birch secondary forest was higher than that in mature poplar-birch secondary forest. The WUE of Fraxinus mandshurica in broad-leaved Korean pine forest was much higher than that in middle-aged poplar-birch secondary forest. The WUE of Acer mono and Quercus mongolica in broad-leaved Korean pine forest was higher than that in mature poplar-birch secondary forest. The dominant tree species had different WUE as for wood types which generally presented ring-porous wood species>diffuse-porous wood species. There were different seasonal trends during the growing season among the dominant species in the broad-leaved Korean pine forest. The WUE of Fraxinus mandshurica, Acer mono, Quercus mongolica and Tilia amurensis showed first decreasing and then increasing, while that of Pinus koraiensis was opposite. The WUE of the broad-leaved Korean pine forest was negatively correlated with temperature in the growing season. The different WUE was one of the strategies for dominant species in the broad-leaved Korean pine forest in Changbai Mountains to adapt to the community succession and respond to climate and environmental change.

Reference carbon cycle dataset for typical Chinese forests via colocated observations and data assimilation.

Chinese forests cover most of the representative forest types in the Northern Hemisphere and function as a large carbon (C) sink in the global C cycle. The availability of long-term C dynamics observations is key to evaluating and understanding C sequestration of these forests. The Chinese Ecosystem Research Network has conducted normalized and systematic monitoring of the soil-biology-atmosphere-water cycle in Chinese forests since 2000. For the first time, a reference dataset of the decadal C cycle dynamics was produced for 10 typical Chinese forests after strict quality control, including biomass, leaf area index, litterfall, soil organic C, and the corresponding meteorological data. Based on these basic but time-discrete C-cycle elements, an assimilated dataset of key C cycle parameters and time-continuous C sequestration functions was generated via model-data fusion, including C allocation, turnover, and soil, vegetation, and ecosystem C storage. These reference data could be used as a benchmark for model development, evaluation and C cycle research under global climate change for typical forests in the Northern Hemisphere.

[Effects of water and nitrogen stress on water utilization of dominant species in broadleaved Korean pine forest in Changbai Mountain, China]. / æ°´æ°®èƒè¿«å¯¹é•¿ç™½å±±é˜”å¶çº¢æ¾æž—ä¼˜åŠ¿æ ‘ç§æ°´åˆ†åˆ©ç”¨çš„å½±å“.

The aggravation of global nitrogen deposition may change plant water utilization and affect plant growth. Understanding the changes of vegetation water consumption under nitrogen deposition is of great significance for simulating and predicting the evolution of each component of forest hydrological cycle. We used the hydrogen and oxygen isotope tracer method to analyze water consumption source, quantity and law of Quercus mongolica (Qm), Fraxinus manshurica (Fm) and Tilia amurensis (Ta), the dominant species in broadleaved Korean pine forest of Changbai Mountain, under different add amounts of nitrogen [low nitrogen addition group (11.8 kg·hm-2·a-1), LN; high nitrogen addition group (23.6 kg·hm-2· a-1), HN] and different amounts of simulated precipitation (water addition amount were 0, 400, 800 and 1600 mL, equivalent to single rainfall amount were 0, 16, 32 and 64 mm, respectively). The results showed that under the condition of relative drought, soil water utilization ratio of Qm, Fm and Ta in the LN group were 26%, 12% and 20%, higher than that in HN group. When the amount of simulated precipitation was 16 mm, soil water utilization ratio of Qm, Fm and Ta in LN group reached the highest, being 73%, 70% and 43%, respectively. This ratio also reached a high value in HN group, but being less than the values in LN group. When the amount of simulated precipitation was 32 mm, soil water content approximated the average value in broadleaved Korean pine forest in the growing season in Changbai Mountain. The average soil water utilization ratio of test tree species in HN group was 39%, higher than that in LN group (16%). When the amount of simulated precipitation reached 64 mm, the soil water was saturation. Soil water utilization ratio of Qm, Fm and Ta in LN group was 14%, 5% and 1%, which was lower than that in HN group, the corresponding ratio were 64%, 13% and 10%, respectively. In conclusion, under the condition of less precipitation and relatively dry soil, the soil water utilization ratio of those three tree species were lower, and the increases of nitrogen availability further reduced the ratio. When the amount of precipitation was high and soil moisture was higher than the average value of the growing season, soil water utilization ratio of those tree species was higher. With the increases of soil nitrogen availability, this ratio was further increased.

Responses of functional traits to seven-year nitrogen addition in two tree species: coordination of hydraulics, gas exchange and carbon reserves.

Atmospheric nitrogen (N) deposition has been observed to impact plant structure and functional traits in terrestrial ecosystems. Although the effect of N deposition on plant water use has been well-evaluated in laboratories and in experimental forests, the linkages between water and carbon relations under N deposition are unclear. Here, we report on hydraulics, gas exchange and carbon reserves of two broad-leaved tree species (Quercus mongolica and Fraxinus mandshurica) in mature temperate forests after a seven-year experiment with different levels of N addition (control (CK), low (23 kg N ha-1 yr-1), medium (46 kg N ha-1 yr-1) and high (69 kg N ha-1 yr-1)). We investigated variation in hydraulic traits (xylem-specific hydraulic conductivity (Ks), native percentage loss of conductivity (PLC) and leaf water potential), xylem anatomy (vessel diameter and density), gas exchange (maximum net photosynthesis rate and stomatal conductance) and carbon reserves (soluble sugars, starch and total nonstructural carbohydrates (NSC)) with different N addition levels. We found that medium N addition significantly increased Ks and vessel diameter compared to control, but accompanied increasing PLC and decreasing leaf water potential, suggesting that N addition results in a greater hydraulic efficiency and higher risk of embolism. N addition promoted photosynthetic capacity via increasing foliar N concentration but did not change stomatal conductance. In addition, we found increase in foliar soluble sugar concentration and decrease in starch concentration with N addition, and positive correlations between hydraulic traits (vessel diameter and PLC) and soluble sugars. These coupled responses of tree hydraulics and carbon metabolism are consistent with a regulatory role of carbohydrates in maintaining hydraulic integrity. Our study provides an important insight into the relationship of plant water transport and carbon dynamics under increasing N deposition.

Photocatalytic degradation of microcystin-LR by modified TiO2 photocatalysis: A review.

Microcystin-LR (MC-LR), the most toxic and commonly encountered cyanotoxin, is produced by harmful cyanobacterial blooms and potentially threatens human and ecosystems health. Titanium dioxide (TiO2) photocatalysis is attracting growing attention and has been considered as an efficient, environmentally friendly and promising solution to eliminate MC-LR in the aquatic ecosystems. Over recent decades, scientific efforts have been directed towards the understanding of fundamentals, modification strategies, and application potentials of TiO2 photocatalysis in degrading MC-LR. In this article, recent reports have been reviewed and progress has been summarized in the development of heterogeneous TiO2-based photocatalysts for MC-LR photodegradation under visible, UV, or solar light. The proposed photocatalytic principles of TiO2 and destruction of MC-LR have been thoroughly discussed. Specifically, some main modification methods for improving the drawbacks and performance of TiO2 nanoparticle were highlighted, including element doping, semiconductor coupling, immobilization, floatability amelioration and magnetic separation. Moreover, the performance evaluation metrics quantum yield (QY) and figure of merit (FOM) were used to compare different photocatalysts in MC-LR degradation. The best performance was seen in N-TiO2 with QY and FOM values of 2.20E-07 molecules/photon and 1.00E-11 mol·L/(g·J·h). N-TiO2 or N-TiO2-based materials may be excellent options for photocatalyst design in terms of MC-LR degradation. Finally, a summary of the remaining challenges and perspectives on new tendencies in this exciting frontier and still an emerging area of research were addressed accordingly. Overall, the present review will offer a deep insight for understanding the photodegradation of MC-LR with modified TiO2 to further inspire researchers that work in associated fields.

Effects of nitrogen additions on mesophyll and stomatal conductance in Manchurian ash and Mongolian oak.

The response of plant CO2 diffusion conductances (mesophyll and stomatal conductances, gm and gsc) to soil drought has been widely studied, but few studies have investigated the effects of soil nitrogen addition levels on gm and gsc. In this study, we investigated the responses of gm and gsc of Manchurian ash and Mongolian oak to four soil nitrogen addition levels (control, low nitrogen, medium nitrogen and high nitrogen) and the changes in leaf anatomy and associated enzyme activities (aquaporin (AQP) and carbonic anhydrase (CA)). Both gm and gsc increased with the soil nitrogen addition levels for both species, but then decreased under the high nitrogen addition level, which primarily resulted from the enlargements in leaf and mesophyll cell thicknesses, mesophyll surface area exposed to intercellular space per unit leaf area and stomatal opening status with soil nitrogen addition. Additionally, the improvements in leaf N content and AQP and CA activities also significantly promoted gm and gsc increases. The addition of moderate levels of soil nitrogen had notably positive effects on CO2 diffusion conductance in leaf anatomy and physiology in Manchurian ash and Mongolian oak, but these positive effects were weakened with the addition of high levels of soil nitrogen.

[Variation characteristics of NDVI and its response to climatic change in the growing season of Changbai Mountain Nature Reserve during 2001 and 2018]. / 2001­2018年长白山自然保护区生长季NDVIå˜åŒ–ç‰¹å¾åŠå ¶å¯¹æ°”å€™å˜åŒ–çš„å“åº”.

To understand the dynamics of temperate forest in Northeast Asia and its response to climate change under the scenario of global change, we examined the temporal and spatial changes of normalized difference vegetation index (NDVI) and their correlation with temperature and precipitation of Changbai Mountain Nature Reserve in the growing season during 2001 and 2018, based on the remote sensing database of MODIS with a resolution of 250 m, land surface temperature data with a resolution of 1 km and meteorological data in the studied and surrounding area. The results showed that, in the growing season of 2001-2018, the averaged NDVI value of the study area was 0.711. Vegetation coverage was relatively high, increasing with a rate of 0.0025·a-1. The temperature showed an extremely significantly increasing trend (0.032 ℃·a-1), the rate of which was higher than that at global level. Precipitation also showed a significantly increasing trend (5.54 mm·a-1) with increased interannual variation. Spatially, NDVI generally was higher in the northwest and decreased with elevation. During the study period, the area with increased NDVI accounted for 46.2%, mainly concentrated in the north and south central high-altitude areas, while 53.8% of total area remained unchanged or slightly decrease. NDVI of the study area was mainly affected by temperature. At the annual scale, NDVI and land surface temperature were positively correlated, with 90.2% presented positive correlation and 43.6% significantly correlated. At the monthly scale, the impact of temperature on NDVI was more significant at the beginning and the end of growing season.

Association between type 2 diabetes and cancer incidence in China: data in hospitalized patients from 2006 to 2013.

BACKGROUND: Evidence of a role for type 2 diabetes in overall cancer risk is limited in ethnic Chinese populations. We therefore investigated whether there is an association between diabetes and cancer incidence. METHODS: All type 2 diabetes and cancer hospitalized patients from the First Affiliated Hospital of Nanjing Medical University between 2006.01 and 2013.12 were eligible for the study. Our research used healthcare information technology and statistical methods to analyze the clinical data of hospitalized patients and explored the relationship between diabetes and cancer. Participants with fasting glucose ≥126 mg/dL, or taking hypoglycemic medications, were classed as having type 2 diabetes. Cancer incidence was established through regular follow-up interviews and medical records. Data were entered into Excel and a database was set up with ACCESS software. Clinical information such as demographics like gender, age, occupation, marriage, insurance and etc., diagnoses, and prescription record were chosen and analyzed. SPSS software was also used for statistical analysis. RESULTS: The number of patients with both diabetes and cancer rose from 220 cases in 2006 to 1,623 cases in 2013. The proportion of cancer patients with diabetes has also increased every year. Younger participants (aged ≤50 years) with diabetes had a greater risk of all cancers [P<0.005, odds ratio (OR) >3.4]. And cancer patients with diabetes occurs more frequently in male patients than in female patients, especially since 2009 the proportion has increased more evidently (P<0.005, OR >1.4). Further analysis showed that the level of blood lipid in patients with diabetes mellitus and cancer was significantly different from that in patients with simple diabetes mellitus (P<0.05). CONCLUSIONS: Our results clearly demonstrate a positive association between diabetes and cancer, especially in younger individuals aged less than 50 years. This finding highlights a need for greater awareness among public health workers and physicians of the importance of effective control of diabetes in the younger population.

Multiyear Measurements on Δ17O of Stream Nitrate Indicate High Nitrate Production in a Temperate Forest.

Nitrification is a crucial step in ecosystem nitrogen (N) cycling, but scaling up from plot-based measurements of gross nitrification to catchments is difficult. Here, we employed a newly developed method in which the oxygen isotope anomaly (Δ17O) of nitrate (NO3-) is used as a natural tracer to quantify in situ catchment-scale gross nitrification rate (GNR) for a temperate forest from 2014 to 2017 in northeastern China. The annual GNR ranged from 71 to 120 kg N ha-1 yr-1 (average 94 ± 10 kg N ha-1 yr-1) over the 4 years in this forest. This result and high stream NO3- loss (4.2-8.9 kg N ha-1 yr-1) suggest that the forested catchment may have been N-saturated. At the catchment scale, the total N output of 10.7 kg N ha-1 yr-1, via leaching and gaseous losses, accounts for 56% of the N input from bulk precipitation (19.2 kg N ha-1 yr-1). This result indicates that the forested catchment is still retaining a large fraction of N from atmospheric deposition. Our study suggests that estimating in situ catchment-scale GNR over several years when combined with other conventional flux estimates can facilitate the understanding of N biogeochemical cycling and changes in the ecosystem N status.

[Applications of compound-specific isotope analysis in tree non-structural carbohydrates research: A review.] / ç‰¹å®šåŒ–åˆç‰©åŒä½ç´ åˆ†æžæŠ€æœ¯åœ¨æ ‘æœ¨éžç»“æž„æ€§ç¢³æ°´åŒ–åˆç‰©ç ”ç©¶ä¸­çš„åº”ç”¨.

Compound-specific isotope analysis (CSIA) can precisely determine the carbon isotopic composition (δ13C) of specific compounds in a complex substrate. The δ13C values in tree non-structural carbohydrates (NSC) compounds, e.g. sugars, organic acids, and sugar alcohols, measured via CSIA could help tracing the newly assimilated photosynthate during carbon transfer and exchange with atmosphere. Further, they can act as sensitive indicators of the physiological response of trees to environmental change. In this review, we first systematically introduced the methods of CSIA with respect to sampling, purification, and analysis. Then, compound-specific δ13C difference among different NSCs and across tree carbon pools, as well as temporal pattern and mechanism underlying the variation of δ13C were described. Finally, we discussed the interaction between δ13C in tree NSCs, the main substrates of respiration, and respired CO2(δ13CR). Further studies on the post-photosynthetic discrimination, tree stress physiology, and tree-ring δ13C formation with the promising applications of CISA were suggested.