Landsat-based spatiotemporal estimation of subtropical forest aboveground carbon storage using machine learning algorithms with hyperparameter tuning.

Introduction: The aboveground carbon storage (AGC) in forests serves as a crucial metric for evaluating both the composition of the forest ecosystem and the quality of the forest. It also plays a significant role in assessing the quality of regional ecosystems. However, current technical limitations introduce a degree of uncertainty in estimating forest AGC at a regional scale. Despite these challenges, remote sensing technology provides an accurate means of monitoring forest AGC. Furthermore, the implementation of machine learning algorithms can enhance the precision of AGC estimates. Lishui City, with its rich forest resources and an approximate forest coverage rate of 80%, serves as a representative example of the typical subtropical forest distribution in Zhejiang Province. Methods: Therefore, this study uses Landsat remote sensing images, employing backpropagation neural network (BPNN), random forest (RF), and categorical boosting (CatBoost) to model the forest AGC of Lishui City, selecting the best model to estimate and analyze its forest AGC spatiotemporal dynamics over the past 30 years (1989-2019). Results: The study shows that: (1) The texture information calculated based on 9×9 and 11×11 windows is an important variable in constructing the remote sensing estimation model of the forest AGC in Lishui City; (2) All three machine learning techniques are capable of estimating forest AGC in Lishui City with high precision. Notably, the CatBoost algorithm outperforms the others in terms of accuracy, achieving a model training accuracy and testing accuracy R2 of 0.95 and 0.83, and RMSE of 2.98 Mg C ha-1 and 4.93 Mg C ha-1, respectively. (3) Spatially, the central and southwestern regions of Lishui City exhibit high levels of forest AGC, whereas the eastern and northeastern regions display comparatively lower levels. Over time, there has been a consistent increase in the total forest AGC in Lishui City over the past three decades, escalating from 1.36×107 Mg C in 1989 to 6.16×107 Mg C in 2019. Discussion: This study provided a set of effective hyperparameters and model of machine learning suitable for subtropical forests and a reference data for improving carbon sequestration capacity of subtropical forests in Lishui City.

Hypericum sampsonii ameliorates radiodermatitis by inhibiting NLRP3 inflammasome activation.

BACKGROUND: Radiodermatitis (RD) is an inflammatory lesion of skin mucosa caused by radiation, which causes itching and pain in patients' skin. Hypericum sampsonii has an anti-inflammatory effect. This study aims to explore the potential effect and mechanism of H. sampsonii on RD. MATERIALS AND METHODS: The RD model was established using X-ray irradiation of mice and the pain response of mice under different treatment methods. Serum levels of IL-1ß, IL-6, and TNF-α were measured by ELSA. The RD cell model was constructed by RAW264.7 cell, H. sampsonii intervention was conducted, and the changes of the NLRP3 inflammasome in the cells were detected by qRT-PCR. The cells were stimulated with LPS and the protein changes of TLR4/NF-κB were investigated by Western Blotting. RESULTS: H. sampsonii can better improve the skin status of RD mice, relieve pain, and reduce the secretion of serum inflammatory factors IL-1ß, IL-6, and TNF-α. H. sampsonii significantly down-regulated the expression of NLRP3, Caspase-1, pro IL-1ß, and IL-1ß. Lps-induced activation of the TLR4/NF-κB pathway promotes the expression of NLRP3 and pro-IL-1ß, and H. sampsonii can inhibit this promotion. CONCLUSION: H. sampsonii may inhibit NLRP3 inflammatory vesicle activation via interfering with TLR4/NF-κB signaling to reduce the inflammatory response in macrophages and thus play a role in the treatment of RD.

Comparative Transcriptome Analysis Reveals the Interaction of Sugar and Hormone Metabolism Involved in the Root Hair Morphogenesis of the Endangered Fir Abies beshanzuensis.

Abies beshanzuensis, an extremely rare and critically endangered plant with only three wild adult trees globally, is strongly mycorrhizal-dependent, leading to difficulties in protection and artificial breeding without symbiosis. Root hair morphogenesis plays an important role in the survival of mycorrhizal symbionts. Due to the lack of an effective genome and transcriptome of A. beshanzuensis, the molecular signals involved in the root hair development remain unknown, which hinders its endangered mechanism analysis and protection. Herein, transcriptomes of radicles with root hair (RH1) and without root hair (RH0) from A. beshanzuensis in vitro plantlets were primarily established. Functional annotation and differentially expressed gene (DEG) analysis showed that the two phenotypes have highly differentially expressed gene clusters. Transcriptome divergence identified hormone and sugar signaling primarily involved in root hair morphogenesis of A. beshanzuensis. Weighted correlation network analysis (WGCNA) coupled with quantitative real-time PCR (qRT-PCR) found that two hormone-sucrose-root hair modules were linked by IAA17, and SUS was positioned in the center of the regulation network, co-expressed with SRK2E in hormone transduction and key genes related to root hair morphogenesis. Our results contribute to better understanding of the molecular mechanisms of root hair development and offer new insights into deciphering the survival mechanism of A. beshanzuensis and other endangered species, utilizing root hair as a compensatory strategy instead of poor mycorrhizal growth.

Intervention effect of group counseling on social support and post-stress growth of orphans and vulnerable children in China.

Orphans and vulnerable children fall under the category of children who are at risk of exposure to more stressful circumstances and receive less social assistance compared to other children. This study aims to investigate the impact of group counseling based on social intervention and psychological therapy (SSGPC) on social support and the perceived stress growth of orphans and vulnerable children. In one special educational needs school in Nanning, China, the SSGPC was developed and implemented. Using the social support and post-stress growth scales, the researchers investigated the effects of SSGPC on orphans and vulnerable children. Twenty-seven orphans and vulnerable children between the ages of nine and 12 were arbitrarily assigned to the experimental and control groups. A pre-test post-test method of quasi-experimental design was applied, with 13 participants in the experimental group and 14 in the control group. The results revealed that the intervention group had significantly higher scores for social support and post-stress growth than the control group. The SSGPC had significantly improved the levels of social support for orphans. The findings indicated that the SSGPC provided an effective way to improve social support and post-stress growth of orphans and vulnerable children.

Effect Analysis of Positive Molecular Therapy in Surgical Nursing Based on Data Transformation Analysis.

This paper briefly introduces the concept, classification, and mechanism of action of positive thinking therapy; reviews the application and research progress of positive thinking therapy in perioperative care of surgical patients at home and abroad; presents the shortcomings and defects in the development; and aims to provide intervention, reference, and basis for the development of positive thinking therapy in perioperative care of surgical patients. One hundred and eight patients are undergoing PCI surgery in our cardiology department; 50 patients undergoing percutaneous coronary intervention were selected as the control group, and 58 patients undergoing percutaneous coronary intervention were selected as the observation group. Traditional health education was employed in the control group, while empowerment education based on timing theory was used in the observation group. The two groups were observed and compared in terms of self-care competence, anxiety and depression, medication adherence score, and exercise adherence. Conclusion. Empowerment education based on timing theory can improve self-care ability of PCI patients, reduce patients' anxiety and depression, and improve patients' medication and exercise compliance.

High-performance, self-powered flexible MoS2 photodetectors with asymmetric van der Waals gaps.

With an urgent demand for low-energy-consumption and wearable devices, it is desirable to find an easy, effective, and low-cost method to fabricate self-powered flexible photodetectors with simple configurations and high-performance. Self-powered photodetectors are normally fabricated based on either two different materials or the same material in contact with two different metal electrodes. Here, a flexible MoS2 photodetector with the same Au electrodes was fabricated on a polyethylene terephthalate (PET) substrate which exhibits self-powered properties. To our knowledge, its configuration is the simplest, and the fabrication process is easy to implement. At a bias of 0 V, the photodetector exhibits a high responsivity of 431 mA W-1, a short response/recovery time of 40 ms/40 ms, and excellent flexibility. Compared with those at a bias of 2 V, a dark current is sufficiently suppressed, and the response/recovery speed is significantly improved. It is found that the driving force of the self-powered photodetector is provided by the asymmetric Schottky barriers originating from the spontaneous generation of two van der Waals gaps with different widths. The asymmetric barriers exist stably at the interfaces between the 2D material and Au electrodes as further observed for ReS2 or GaSe flakes, which show the generality of asymmetric Schottky barriers between the 2D material and Au electrodes. The discovery here thus gives a new way to generate asymmetric Schottky barriers and develop high-performance self-powered photodetectors.

Noninvasive measurement of the vital signs of cancer patients with a dual-path microbend fiber sensor.

A novel dual-path microbend fiber optic sensor is designed for noninvasive measurement of respiratory rate (RR) and heart rate (HR) for cancer patients. The performance of the microbend fiber sensor is assessed in two groups of cancer patients, cancer patients with pain and without pain, ranging from eighteen to ninety-six years old in a daily observational measurement with the sensor mattress under the mattress of the clinical bed. All the patients received standard clinical monitoring for evaluating the accuracy of our measurement results. The results of our study showed good consistency in the experimental results of RR and HR between the dual-path fiber sensor we proposed and the hospital equipment with average errors of 3.60 beats per minute (bpm) and 1.02 respiration per minute (rpm) in HR and RR measurement in cancer patients with pain and 1.87bpm and 1.27rpm in HR and RR measurement in cancer patients without pain, respectively. In HR monitoring, the single path microbend fiber optic sensor has 8035 minutes of data with a false report rate of 19.09%, while the dual-path microbend fiber optic sensor has 6188 minutes of data with a false report rate of 12.87%. The dual-path sensor has a smaller false report rate compared with the single path sensor due to pre-judgments of data with path 1 and path 2. To our best knowledge, it is the first time to propose and demonstrate a dual-path sensor to reduce the false report rate for HR and RR measurements. The results of the Blend-Altman method showed great agreement between our sensor and hospital standard monitor in HR and RR measurements. The independent sample t-test indicates that the HR of cancer patients may be an effective way to judge whether or not they have cancer pain. Our noninvasive dual-path microbend fiber sensor also showed the advantages of an easy fabrication process, simple structure, and low false report rate.

Perceived Stress, Social Support, Emotional Intelligence, and Post-Stress Growth among Chinese Left-Behind Children: A Moderated Mediation Model.

BACKGROUND: Several previous studies have revealed a negative impact of perceived stress on post-stress growth. Nevertheless, the potential mediating and moderating mechanisms are unclear, particularly for left-behind children in China. Therefore, this study aims to investigate the negative relationship between perceived stress and post-stress growth, the mediating effect of social support, as well as the moderating effect of emotional intelligence in a sample of Chinese left-behind children. METHODS: A sample of 837 Chinese students in elementary and middle school was collected for this study. The Perceived Stress Scale, the Social Support Scale, the Emotional Intelligence Scale, and the Post-Stress Growth Scale were employed to examine them. The data were analyzed using SPSS 25.0 software. RESULTS: The results indicate a significant negative association between perceived stress and post-stress growth. Among perceived stress and social support, the former acted as a mediator, while the latter as a moderator. This study sheds light on the post-stress growth of Chinese left-behind children. The findings validated a model of moderated mediation that shows the relationship between perceived stress, emotional intelligence, social support, and post-stress growth. CONCLUSION: This study confirmed that social support is one of the most important factors among left-behind children, from perceived stress to post-stress growth. Furthermore, the study reveals that emotional intelligence can adjust the relationship between perceived stress and social support to post-stress growth. Therefore, for both family education and school education, the result provides a new direction.

Comparing strategy of immune checkpoint inhibitors plus chemotherapy with chemotherapy alone for small cell lung cancer: a meta-analysis based on six RCTs incorporating 2800 participants.

OBJECTIVES: The project is designed to compare the clinical efficacy and adverse events resulting from immune checkpoint inhibitors (ICIs) plus chemotherapy and chemotherapy alone in patients with small cell lung cancer (SCLC). METHODS: PubMed Database and ClinicalTrials.gov were both searched to identify randomized controlled clinical trials for assessing ICIs in all-stage SCLC. After screening in strict accordance with the inclusion and exclusion criteria, eligible studies were evaluated in regard to the population, intervention, comparator, outcome as well as study design (PICOS) pattern. Furthermore, primary endpoints of these randomized controlled trials (RCTs) included overall survival (OS), progression-free survival (PFS) and complete/objective response rate (CRR/ORR). Statistical analyses were realized via Review Manager Version 5.3 Software. RESULTS: Compared with the chemotherapy alone group, the ICIs plus chemotherapy group significantly improved with respect to such indicators as OS (hazard ratio (HR) = 0.82, 95% CI 0.74-0.90, P < 0.0001), PFS (HR = 0.80, 95% CI 0.74-0.87, P < 0.00001) and ORR (64.7% versus 59.1%). According to the safety analysis, the incidence of treatment-related adverse events (trAEs) at all grades was higher in ICIs plus chemotherapy group (OR = 1.59, 95% CI 1.20-2.10, P = 0.001), bearing no statistical significance at grade 3 or above (OR = 1.21, 95% CI 0.99-1.49, P = 0.07). CONCLUSIONS: The combination of ICIs and chemotherapy witnessed better anti-neoplastic efficacy for SCLC. Moreover, the incidence of trAEs at all grades was elevated in ICIs plus chemotherapy group, with little discrepancy in both groups at grade 3 or above.

The impact of antibiotics on efficacy of immune checkpoint inhibitors in malignancies: A study based on 44 cohorts.

BACKGROUND: Pre-clinical and clinical data had revealed the gut microbiome plays a critical role in immune checkpoint inhibitors (ICIs) efficacy. This study was designed to investigate whether antibiotics (ATBs) affect the prognosis of malignancies treated with ICIs. METHODS: Electronic databases were searched to identify relevant trials that evaluated the impact of ATBs on ICIs efficacy. The primary endpoints were overall survival (OS) and progression-free survival (PFS) measured by HRs with corresponding 95%CIs. Subgroup analyses were performed based on cancer type, study design, ICIs agent, and time of ATBs administration. RESULTS: Totally, 12,492 individuals in the 44 cohorts were recruited. Pooled results showed that ATBs administration was significantly correlated with a worse objective remission rate (ORR) (OR = 0.61, 95%CI (0.42-0.90), P = 0.0128), PFS (HR = 1.18, 95%CI (1.11-1.25), P < 0.0001), and OS (HR = 1.20, 95%CI (1.15-1.25), P < 0.0001) in patients treated with ICIs. In subgroup analyses, patients treated with ICIs exposed to ATBs suffered an evidently worse ORR in arms of renal cell carcinoma (RCC) (OR = 0.30, 95%CI (0.14-0.67), P = 0.0034), multiple (OR = 0.44, 95%CI (0.27-0.73), P = 0.0016), and before ICIs initiation (OR = 0.47, 95%CI (0.32-0.71), P = 0.0003) without heterogeneity; experienced a worse PFS and OS in arms of non-small cell lung cancer, melanoma, RCC, urothelial carcinoma, multiple, prospective, retrospective, PD-(L)1 alone, PD-(L)1 plus CTLA-4, before ICIs initiation, before ICIs initiation and concurrent, and before or after ICIs within 1 month, while a better PFS and OS in concurrent with ICIs arm. CONCLUSIONS: ATBs administration was negatively associated with ORR, PFS and OS in malignancies treated with ICIs, while the time of ATBs exposure might impact ICIs efficacy.

Fatal toxic effects related to EGFR tyrosine kinase inhibitors based on 53 cohorts with 9,569 participants.

BACKGROUND: To estimate the incidence and susceptible factors of fatal toxic effects related to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). METHODS: PubMed and Embase were thoroughly searched for clinical trials based on the following terms and corresponding Medical Subject Heading ones: "erlotinib", "gefitinib", "afatinib", "dacomitinib", "osimertinib", and "non-small-cell lung cancer (NSCLC)". A total of 53 eligible cohorts with 9,569 participants were collected. RESULTS: A total of 105 cases of fatal toxic effects related to EGFR-TKIs occurred in 53 cohorts. The overall incidence was 1.33% [95% confidence interval (CI): 1.08-1.63%]. The odds and incidence were apparently higher in Japanese group (compared with non-East Asian group) [2.72 vs. 1.30, P=0.015; odds ratio (OR): 2.26, 95% CI: 1.17-4.37, P=0.015], in first-line treatment group (compared with EGFR-TKI retreatment group) (1.54 vs. 0.69, P=0.028; OR: 2.41, 95% CI: 1.10-5.26, P=0.028), and in the trial phase II (compared with trial phase III) (1.82% vs. 1.11%, P=0.009; OR: 1.73, 95% CI: 1.15-2.62, P=0.009). Notably, the Japanese group was higher than non-East Asian group after controlling for the treatment-line and trial phase (OR: 2.16, 95% CI: 1.12-4.16, P=0.022). Interstitial lung disease (ILD) was predominant in 29 fatal causes followed by pneumonia, respiratory failure and diarrhea. CONCLUSIONS: The overall incidence of fatal toxic effects related to EGFR-TKIs was 1.33%, and the major fatal cause was ILD, followed by pneumonia, respiratory failure and diarrhea. The susceptible factor of fatal toxic effects related to EGFR-TKIs was the Japanese group. This study provided a capability for clinicians to predict and detect high-risk populations of fatal toxic effects.

Association between NAFLD and risk of prevalent chronic kidney disease: why there is a difference between east and west?

BACKGROUNDS: There is a discrepancy between west and east on the relationship between non-alcoholic fatty liver disease (NAFLD) and chronic kidney disease (CKD). This study aimed to find out the possible reason for this and to clarify the association between NAFLD and CKD by analyzing two population-based datasets from the US and China. METHODS: Two health examination datasets from China and the US were used. CKD was defined as an estimated glomerular filtration rate (eGFR) < 60 ml/min/1.73m2 or and/or abnormal albuminuria and/or overt proteinuria. Binary logistic regression was used to examine the association between NAFLD and CKD. RESULTS: A total of 60,965 participants were analyzed, including 11,844 from the US and 51,229 from China. The prevalence of NAFLD was 27.12% in the Chinese population and 36.08% in the US population (p < 0.001). The proportions of CKD and late stage CKD (stages 3-5) were higher in the US population than the Chinese one. NAFLD was independently associated with an increased risk of CKD in Chinese population, whereas in the US population, the NAFLD was not an independent risk factor of CKD. In subgroup analyses which excluded late stages CKD (stages 3-5), the risks of mild renal function decline became consistent: NAFLD was associated with early stages of CKD but not the late stages of CKD in both populations. CONCLUSION: NAFLD increased the risk of early stages of CKD in both Chinese and the US population. The conflicting results reported by previous studies might result from the different proportion of late stages of CKD.

Correction to: Predictive value of positron emission tomography for the prognosis of immune checkpoint inhibitors (ICIs) in malignant tumors.

The original version of this article unfortunately contained a mistake. The correct information is given in the following.

Predictive value of positron emission tomography for the prognosis of immune checkpoint inhibitors (ICIs) in malignant tumors.

PURPOSE: This study aimed at investigating the value of applying positron emission tomography (PET) to early predict the effect of immune checkpoint inhibitors (ICIs) in malignant tumors. METHODS: Electronic databases MEDLINE/PubMed, EMBASE, and Cochrane Library were searched to identify relevant trials. The primary endpoints were progression-free survival (PFS) and overall survival (OS). The results were analyzed utilizing Stata 12.0 statistical software. Subgroup analyses were implemented based on primary tumors, study designs, continents, type of ICIs, evaluation index of PET, and evaluated PET timing. RESULTS: Fifteen studies incorporating 664 individuals were eligible. Compared with PET nonresponse group, PET response group displayed a significantly prolonged PFS (HR 0.27, 95% CI [0.16, 0.44]; P < 0.001) and OS (HR 0.56, 95% CI [0.48, 0.65]; P < 0.001). Analogical outcomes were obtained in subgroup analyses of PFS in non-small cell lung cancer, prospective, America, ipilimumab, nivolumab/pembrolizumab combined ipilimumab, PET Response Criteria in Solid Tumors (PERCIST), baseline PET and early PET timing arms without heterogeneity; so did OS in melanoma, retrospective, Europe, America, ipilimumab, nivolumab/pembrolizumab, PERCIST, baseline metabolic tissue volume, baseline standard uptake value, and baseline total lesion glycolysis, baseline PET timing, early PET timing and late PET timing arms. CONCLUSION: Our study demonstrated that PET was a promising approach to early predict the prognosis of ICIs for malignancies.

Association between Vitamin D Status and Non-Alcoholic Fatty Liver Disease: A Population-Based Study.

The relationship between vitamin D levels and non-alcoholic fatty liver disease (NAFLD) remains unestablished. In this study, we aimed to explore the relationship between vitamin D levels and NAFLD based on population survey data. This cross-sectional study was conducted based on data from the National Health and Nutrition Examination Survey. Liver steatosis was diagnosed by ultrasonography. Binary logistic regression analyses were performed to determine the relationship between vitamin D status and NAFLD. A total of 9,782 participants were identified in this analysis, with 46.8% male and an average age of 44.41±0.16 y old. Among them, 6,047 (61.8%) cases were without NAFLD, 1,357 (13.9%) had mild NAFLD, 1,594 (16.3%) had moderate and 784 (8.0%) had severe NAFLD. Compared to those with non-NAFLD or mild NAFLD, patients in the moderate to severe NAFLD group had higher vitamin D deficiency or insufficiency rates (12.4% vs 11.5% and 36.8% vs 33.2%, respectively). After adjustment for male gender, older age, race, BMI, history of diabetes and vitamin D intake, vitamin D levels were independently associated with the severity of NAFLD (vitamin D deficiency group OR: 1.314, 95% CI: 1.129 to 1.529, vitamin D insufficiency group OR: 1.203, 95% CI: 1.090 to 1.328). Besides that, cold season was also found to be an independent factor for NAFLD (OR: 0.896, 95% CI: 0.820 to 0.979). Lower vitamin D level is an independent risk factor for NAFLD. Vitamin D levels are inversely associated with the severity of NAFLD. Cold season increases the risk of NAFLD independently.

Effects of calcium and estrogen on the development of the ceratohyal cartilage in zebrafish (Danio rerio) larvae upon embryo and maternal cadmium exposure.

The present study is to investigate the reason why the ceratohyal cartilage (CH) angle of zebrafish larvae were larger compared to the control group after their female parents were treated with cadmium (F-Cd). However, the CH angle was smaller compared to the control group when embryos were directly exposed to Cd2+ for 72 h (D-Cd). Results showed that calcium contents of larvae were lower than the control, but the transporter isoforms trpv4 and trpv6 mRNA expressions were significantly increased upon D-Cd treatment. Furthermore, external Ca2+ added during D-Cd treatment reveals that the CH angles of larvae did not appear significantly different compared to the control. On the other hand, E2 (17ß-estradiol) contents were higher around 1.9 folds in the ovaries of females; CH angle were over 25°, and Cd2+ contents were higher around 6 folds than the control group on larvae treated through F-Cd treatment; CH angles and E2 levels on larvae were higher than the control after the larvae were treated with 1.84 µM E2 (D-E2); Estradiol receptor (ER) isoforms ERß1 and ERα mRNA expressions significantly increased when 0 hpf embryos were either treated with D-E2 or D-Cd. According to the results, we suggested that the CH angle of larvae become larger upon F-Cd treatment due to maternal Cd2+ inducing E2 levels. However, the CH angle of larvae appeared to be smaller compared to the control upon D-Cd treatment. We suggested that the CH angle decreased due to the decrease of Ca2+ contents upon Cd2+ exposure.

Analyzing the effectiveness of using branchial NKA activity as a biomarker for assessing waterborne copper toxicity in tilapia (Oreochromis mossambicus): A damage-based modeling approach.

Branchial Na(＋)-K(＋)-ATPase (NKA) activity has been suggested as a promising biomarker for assessing metal stress in aquatic organisms. However, studies that systematically show the effectiveness of using NKA activity to detect metal exposure and toxicity at the individual level are limited. In this study, we aimed to determine whether branchial NKA activity mechanistically responds to the accumulation of waterborne copper (Cu) and accounts for observed toxicity over time under environmentally-relevant and aquafarming Cu exposure levels (0.2, 1 and 2 mg L(-1)). Temporal trends in Cu accumulation and the corresponding responses of branchial NKA activity resulting from Cu exposure were investigated in laboratory experiments conducted on juvenile tilapia (Oreochromis mossambicus), a freshwater teleost that shows potential as a bioindicator of real-time and historical metal pollution. We used the process-based damage assessment model (DAM) to inspect the time course of Cu toxicity by integrating the compensation process between Cu-induced inhibition and repair of branchial NKA activity. NKA activity acted as a sensitive biomarker for Cu exposure and accumulation in tilapia, which showed induced impairment of osmoregulation and lethality when they were exposed to environmentally relevant levels (0.2 mg L(-1)), but not to higher exposure levels (1 and 2 mg L(-1)) in aquaculture farms or contaminated aquatic ecosystems. This study highlights the benefits and limitations of using branchial NKA activity as a sensitive biomarker to assess the health status of a fish population and its ecosystem.

Magnetite nanoparticle-induced fluorescence quenching of adenosine triphosphate-BODIPY Conjugates: application to adenosine triphosphate and pyrophosphate sensing.

We report that magnetite nanoparticles (Fe3O4 NPs) act as an efficient quencher for boron dipyrromethene-conjugated adenosine 5'-triphosphate (BODIPY-ATP) that is highly fluorescent in bulk solution. BODIPY-ATP molecules attached to the surface of Fe3O4 NPs through the coordination between the triphosphate group of BODIPY-ATP and Fe(3+)/Fe(2+) on the NP surface. The formed complexes induced an apparent reduction in the BODIPY-ATP fluorescence resulting from an oxidative-photoinduced electron transfer (PET) from the BODIPY-ATP excited state to an unfilled d shell of Fe(3+)/Fe(2+) on the NP surface. A comparison of the Stern-Volmer quenching constant between Fe(3+) and Fe(2+) suggests that Fe(3+) on the NP surface dominantly controls this quenching process. The efficiency for Fe3O4 NP-induced fluorescence quenching of the BODIPY-ATP was enhanced by increasing the concentration of Fe3O4 NPs and lowering the pH of the solution to below 6.0. We found that pyrophosphate and ATP compete with BODIPY-ATP for binding to Fe3O4 NPs. Thus, we amplified BODIPY-ATP fluorescence in the presence of increasing the pyrophosphate and ATP concentration; the detection limits at a signal-to-noise ratio of 3 for pyrophosphate and ATP were determined to be 7 and 30 nM, respectively. The Fe3O4 NP-based competitive binding assay detected ATP and pyrophosphate in only 5 min. The selectivity of this assay for ATP over metal ions, amino acids, and adenosine analogues is particularly high. The practicality of using the developed method to determine ATP in a single drop of blood is also validated.

Spirulina prevents memory dysfunction, reduces oxidative stress damage and augments antioxidant activity in senescence-accelerated mice.

Spirulina has proven to be effective in treating certain cancers, hyperlipidemia, immunodeficiency, and inflammatory processes. In this study, we aimed to investigate the effects of Spirulina on memory dysfunction, oxidative stress damage and antioxidant enzyme activity. Three-month-old male senescence-accelerated prone-8 (SAMP8) mice were randomly assigned to either a control group or to one of two experimental groups (one receiving daily dietary supplementation with 50 mg/kg BW and one with 200 mg/kg BW of Spirulina platensis water extract). Senescence-accelerated-resistant (SAMR1) mice were used as the external control. Results showed that the Spirulina-treated groups had better passive and avoidance scores than the control group. The amyloid ß-protein (Aß) deposition was significantly reduced at the hippocampus and whole brain in both Spirulina groups. The levels of lipid peroxidation were significantly reduced at the hippocampus, striatum, and cortex in both Spirulina groups, while catalase activity was significantly higher only in the 200 mg/kg BW Spirulina group than in the control group. Glutathione peroxidase activity was significantly higher only in the cortex of the 200 mg/kg group than in that of the SAMP8 control group. However, superoxide dismutase activity in all parts of the brain did not significantly differ among all groups. In conclusion, Spirulina platensis may prevent the loss of memory possibly by lessening Aß protein accumulation, reducing oxidative damage and mainly augmenting the catalase activity.

Cadmium concentration and metallothionein expression in prostate cancer and benign prostatic hyperplasia of humans.

BACKGROUND/PURPOSE: Cadmium (Cd) causes various genitourinary disorders and is a carcinogen for prostate cancer. Metallothionein (MT) is a protein that detoxifies heavy metals. We evaluated changes in Cd concentration and MT expression in human prostate cancer (CaP) and benign prostatic hyperplasia (BPH). Our goal was to clarify the relationship between Cd concentration and MT expression in prostatic diseases. METHODS: The experimental group consisted of 18 patients who underwent radical prostatectomy for CaP. The control group consisted of 35 patients who underwent transurethral resection of the prostate for BPH. Tissue samples were acquired from the gross tumor site and from resected chips. We determined Cd concentration by atomic absorption, MT expression by immunoblotting, and immunohistochemical staining. The significance of between-group differences for these outcomes was analyzed using Student's t tests. RESULTS: There was no statistically significant difference in Cd concentration between the CaP and BPH groups. Immunoblots from both groups revealed a single band. The relative intensity of the MT band was 0.58 +/- 0.09 in the BPH group and 0.17 +/- 0.03 in the CaP group. MT expression in patients with BPH was 3.4-fold higher than in those with CaP. CONCLUSION: MT may bind heavy metals and protect patients from CaP. Additional studies are needed to reveal the factors that influence the expression of MT in prostate epithelial cells, and to analyze the free and compound forms of Cd at the same time.