Land degradation neutrality assessment and factors influencing it in China's arid and semiarid regions.

The ecosystems in China's arid and semiarid regions are notably fragile and experiencing dramatic land degradation. At the 12th Conference of the Parties (COP12) to the United Nations Convention to Combat Desertification (UNCCD) in October 2015, a definition for land degradation neutrality (LDN) was proposed and subsequently integrated into the Sustainable Development Goals (SDGs). Research on LDN has developed in terms of conceptual framework constructions, quantitative assessments, and empirical studies. However, LDN and its drivers must be clarified in China's arid and semiarid regions since some representative processes have yet to be fully considered in the assessment. Here, we develop an LDN indicator system specialised for the area, assess their LDN status, and determine the impacts of human activities and climate change on LDN. Our research aims to refine the LDN indicator system tailored for China's arid and semiarid regions by incorporating the trends of wind and water erosion. We also identify the influence of human activity and climate change on LDN, which provides insightful strategies for ecological restoration and sustainable development in drylands with climate-sensitive ecosystems. The results show that: (1) In 2020, more than half of areas of China's arid and semiarid regions achieved LDN, with more pronounced success in the southeastern areas compared to the central regions. (2) For LDN drivers, elevation shows negligible influence on LDN, whereas increased temperature promotes LDN achievement. Conversely, factors like vapour pressure deficit and v-direction wind speed hinder it. In conclusion, China's arid and semiarid regions achieved LDN, and the dominant factor that substantially influences LDN varies across geographical zones, with higher wind speeds and elevated GDP levels generally obstructing LDN in most areas.

Active Probe Atomic Force Microscopy with Quattro-Parallel Cantilever Arrays for High-Throughput Large-Scale Sample Inspection.

An Atomic Force Microscope (AFM) is a powerful and versatile tool for nanoscale surface studies to capture 3D topography images of samples. However, due to their limited imaging throughput, AFMs have not been widely adopted for large-scale inspection purposes. Researchers have developed high-speed AFM systems to record dynamic process videos in chemical and biological reactions at tens of frames per second, at the cost of a small imaging area of up to several square micrometers. In contrast, inspecting large-scale nanofabricated structures, such as semiconductor wafers, requires nanoscale spatial resolution imaging of a static sample over hundreds of square centimeters with high productivity. Conventional AFMs use a single passive cantilever probe with an optical beam deflection system, which can only collect one pixel at a time during AFM imaging, resulting in low imaging throughput. This work utilizes an array of active cantilevers with embedded piezoresistive sensors and thermomechanical actuators, which allows simultaneous multi-cantilever operation in parallel operation for increased imaging throughput. When combined with large-range nano-positioners and proper control algorithms, each cantilever can be individually controlled to capture multiple AFM images. With data-driven post-processing algorithms, the images can be stitched together, and defect detection can be performed by comparing them to the desired geometry. This paper introduces principles of the custom AFM using the active cantilever arrays, followed by a discussion on practical experiment considerations for inspection applications. Selected example images of silicon calibration grating, highly-oriented pyrolytic graphite, and extreme ultraviolet lithography masks are captured using an array of four active cantilevers ("Quattro") with a 125 µm tip separation distance. With more engineering integration, this high-throughput, large-scale imaging tool can provide 3D metrological data for extreme ultraviolet (EUV) masks, chemical mechanical planarization (CMP) inspection, failure analysis, displays, thin-film step measurements, roughness measurement dies, and laser-engraved dry gas seal grooves.

Camrelizumab Plus Apatinib and Temozolomide as First-Line Treatment in Patients With Advanced Acral Melanoma: The CAP 03 Phase 2 Nonrandomized Clinical Trial.

Importance: Acral melanoma, known for low tumor mutation burden, responds poorly to immunotherapy. A standard therapy is still lacking. Objective: To investigate the activity and safety of camrelizumab (an anti-programmed cell death-1 antibody) plus apatinib (a vascular endothelial growth factor receptor 2 inhibitor) and temozolomide as first-line treatment in patients with advanced acral melanoma. Design, Setting, and Participants: In this single-arm, single-center, phase 2 nonrandomized clinical trial, patients with treatment-naive unresectable stage III or IV acral melanoma were enrolled at Peking University Cancer Hospital and Institute between June 4, 2020, and August 24, 2021. The data cutoff date was April 10, 2022. Interventions: Patients received 4-week cycles of intravenous camrelizumab, 200 mg, every 2 weeks; oral apatinib 250 mg, once daily; and intravenous temozolomide, 200 mg/m2, once daily on days 1 to 5 until disease progression or unacceptable toxic effects. Main Outcomes and Measures: The primary end point was objective response rate as assessed by investigators according to the Response Evaluation Criteria In Solid Tumors (version 1.1). Secondary end points included progression-free survival, time to response, duration of response, disease control rate, overall survival, and safety. Results: A total of 50 patients (32 men [64%]; median age, 57 years [IQR, 52-62 years]) were enrolled and received treatment. The median follow-up duration was 13.4 months (IQR, 9.6-16.2 months). The objective response rate was 64.0% (32 of 50; 95% CI, 49.2%-77.1%). The median time to response and duration of response were 2.7 months (IQR, 0.9-2.9 months) and 17.5 months (95% CI, 12.0 to not reached), respectively. The disease control rate was 88.0% (44 of 50; 95% CI, 75.7%-95.5%). The estimated median progression-free survival was 18.4 months (95% CI, 10.6 to not reached). The median overall survival was not reached. The most common grade 3 or 4 treatment-related adverse events were increased gamma-glutamyltransferase levels (15 [30%]), decreased neutrophil count (11 [22%]), increased conjugated bilirubin levels (10 [20%]), and increased aspartate aminotransferase levels (10 [20%]). No treatment-related deaths occurred. Conclusions and Relevance: The findings of this nonrandomized clinical trial suggest that camrelizumab plus apatinib and temozolomide may be a potential first-line treatment option for patients with advanced acral melanoma, which warrants further validation in a randomized clinical trial. Trial Registration: ClinicalTrials.gov Identifier: NCT04397770.

Review: Advanced Atomic Force Microscopy Modes for Biomedical Research.

Visualization of biomedical samples in their native environments at the microscopic scale is crucial for studying fundamental principles and discovering biomedical systems with complex interaction. The study of dynamic biological processes requires a microscope system with multiple modalities, high spatial/temporal resolution, large imaging ranges, versatile imaging environments and ideally in-situ manipulation capabilities. Recent development of new Atomic Force Microscopy (AFM) capabilities has made it such a powerful tool for biological and biomedical research. This review introduces novel AFM functionalities including high-speed imaging for dynamic process visualization, mechanobiology with force spectroscopy, molecular species characterization, and AFM nano-manipulation. These capabilities enable many new possibilities for novel scientific research and allow scientists to observe and explore processes at the nanoscale like never before. Selected application examples from recent studies are provided to demonstrate the effectiveness of these AFM techniques.

An inverted U-shaped curve relating farmland vulnerability to biological disasters: Implications for sustainable intensification in China.

Sustainable farmland intensification is necessary in order to harmonize relationships between food security, socioeconomic development, and ecological civilization. However, the degradation of farmland sustainability because of biological disasters represents a major challenge if we are to achieve this intensification. Our understanding of farmland vulnerability to biological disasters (FVBD) remains relatively rudimentary and subjective, limiting its effectiveness as a tool for farmland sustainability analysis. Limited research has also been carried out on FVBD changes taking into account human decisions on farmland use. The aim of this study is to achieve a novel understanding of FVBD change and its implications for sustainable intensification using evidence from Chinese farmland use. A theoretical framework based on an inverted U-shaped curve that depicts FVBD as well as an assessment framework for FVBD were established using induced substitution of agricultural production. Across China and considering 15 provincial districts with scarce farmland, the relationship between FVBD and socio-economic development was identified as consistent with an inverted U-shaped curve at both national and provincial levels. FVBD values in 2016 across Southern China, on the Huang-Huai-Hai Plain, and on the middle-lower Yangtze Plain were 45.44, 40.58, and 37.22, respectively. These values also decreased in provinces on the middle-lower Yangtze Plain between 1995 and 2016, but increased markedly across provinces in Southern China and on the Huang-Huai-Hai Plain. Contributions to FVBD changes during stages of growth and decline were also analyzed between 1995 and 2016. An inverted U-shaped curve was effective in investigating the responses of farmland sustainability to a range of alternative future socioeconomic development pathways. Thus, in the Chinese settings, a typical country with scarce farmland, policies on FVBD control are essential if we are to promote sustainable farmland intensification. The findings of this work are important and present us with a new way to understand FVBD from a human perspective.

Lights Out! Nano-Scale Topography Imaging of Sample Surface in Opaque Liquid Environments with Coated Active Cantilever Probes.

Atomic force microscopy is a powerful topography imaging method used widely in nanoscale metrology and manipulation. A conventional Atomic Force Microscope (AFM) utilizes an optical lever system typically composed of a laser source, lenses and a four quadrant photodetector to amplify and measure the deflection of the cantilever probe. This optical method for deflection sensing limits the capability of AFM to obtaining images in transparent environments only. In addition, tapping mode imaging in liquid environments with transparent sample chamber can be difficult for laser-probe alignment due to multiple different refraction indices of materials. Spurious structure resonance can be excited from piezo actuator excitation. Photothermal actuation resolves the resonance confusion but makes optical setup more complicated. In this paper, we present the design and fabrication method of coated active scanning probes with piezoresistive deflection sensing, thermomechanical actuation and thin photoresist polymer surface coating. The newly developed probes are capable of conducting topography imaging in opaque liquids without the need of an optical system. The selected coating can withstand harsh chemical environments with high acidity (e.g., 35% sulfuric acid). The probes are operated in various opaque liquid environments with a custom designed AFM system to demonstrate the imaging performance. The development of coated active probes opens up possibilities for observing samples in their native environments.

Preconditioning with carbon monoxide inhalation promotes retinal ganglion cell survival against optic nerve crush via inhibition of the apoptotic pathway.

Optic neurodegeneration, in addition to central nervous trauma, initiates impairments to neurons resulting in retinal ganglion cell (RGC) damage. Carbon monoxide (CO) has been observed to elicit neuroprotection in various experimental models. The present study investigated the potential retinal neuroprotection of preconditioning with CO inhalation in a rat model of optic nerve crush (ONC). Adult male Sprague­Dawley rats were preconditioned with inhaled CO (250 ppm) or air for 1 h prior to ONC. Animals were euthanized at 1 or 2 weeks following surgery. RGC densities were quantified by hematoxylin and eosin (H&E) staining and FluoroGold labeling. Visual function was measured via flash visual evoked potentials (FVEP). Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining, and caspase­9 and caspase­3 activity in the retinas, were assessed at 2 weeks post­ONC. The RGC density of CO + crush rats was significantly increased compared with that of the corresponding crush­only rats at 2 weeks (survival rate, 66.2 vs. 48.2% as demonstrated by H&E staining, P<0.01; and 67.6 vs. 37.6% as demonstrated by FluoroGold labeling, P<0.05). FVEP measures indicated a significantly better­preserved latency and amplitude of the P1 wave in the CO + crush rats compared with the crush­only rats. The TUNEL assays demonstrated fewer apoptotic cells in the CO + crush group compared with the crush­only group, accompanied by the suppression of caspase­9 and caspase­3 activity. The results of the present study suggested that inhaled CO preconditioning may be neuroprotective against ONC insult via inhibition of neuronal apoptosis.

Pioglitazone ameliorates retinal ischemia/reperfusion injury via suppressing NLRP3 inflammasome activities.

AIM: To explore the role of Pioglitazone (Pio) on a mouse model of retinal ischemia/reperfusion (I/R) injury and to elucidate the potential mechanism. METHODS: Retinal ischemia was induced in mice by increasing the intraocular pressure, and Pio was administered 4h though periocular injection before I/R. The number of cells in the ganglion cell layer (GCL) was counted 7d after retinal I/R injury. Glial fibrillary acidic protein (GFAP), nuclear factor-kappa B (NF-κB), p38, phosphorylated-p38, PPAR-γ, interleukin-1ß (IL-1ß), Toll-like receptor 4 (TLR4), NLRP3, cleaved caspase-1, caspase-1 were determined by real-time polymerase chain reaction and Western blotting. RESULTS: Pio promoted the survival of retinal cells in GCL following retinal I/R injury (P<0.05). Besides, retinal I/R injury stimulated the expression of GFAP and TLR4, which were partially reversed by Pio treatment (P<0.05). Retinal I/R injury-upregulated expression of NLRP3, cleaved caspase-1, IL-1ß was attenuated after Pio treatment (P<0.05). Moreover, I/R injury induced activation of NF-κB and p38 were inhibited by Pio treatment (P<0.05). CONCLUSION: Pio promotes retinal ganglion cells survival by suppressing I/R-induced activation of TLR4/NLRP3 inflammasomes via inhibiting NF-κB and p38 phosphorylation.

Nogo-B Promotes Angiogenesis in Proliferative Diabetic Retinopathy via VEGF/PI3K/Akt Pathway in an Autocrine Manner.

BACKGROUND/AIMS: Nogo-B, a conservative protein of endoplasmic reticulum, is a member of the reticulon family of proteins. Proliferative diabetic retinopathy (PDR) is the major concerning problem of diabetic retinopathy. This study explored the role of Nogo-B in the regulation of angiogenesis in PDR patients and primary human retinal endothelial cells (HRMECs). METHODS: Nogo-B was down-regulated through the use of Lentivirus-NogoB-RNAi, the effects of Nogo-B on angiogenesis under high glucose stimulation were evaluated via CCK-8 assay, wound closure assay, transwell assay, and tube formation assay. Expression of Nogo-B, VEGF, PI3K and Akt were determined by western blotting, immunofluorescence, enzyme-linked immunosorbent assay (ELISA). Co-culture systerm was used to explore cell communication. RESULTS: Nogo-B was highly enriched in ocular tissues of PDR patients and in HRMECs exposed to high glucose. Down-regulation of Nogo-B attenuated high glucose induced cell migration and tube formation in HRMECs. Mechanistically, in comparison with the negative control group, Lentivirus-NogoB-RNAi group had exhibited reduced VEGF secretion, weakened PI3K and Akt activation. Besides, high glucose treatment promoted the secretion of Nogo-B and presented as a "long-term memory". CONCLUSIONS: These data collectively indicated that Nogo-B promoted angiogenesis in HRMECs via VEGF/PI3K/Akt pathway in an autocrine manner.

Methane rescues retinal ganglion cells and limits retinal mitochondrial dysfunction following optic nerve crush.

Secondary degeneration is a common event in traumatic central nervous system disorders, which involves neuronal apoptosis and mitochondrial dysfunction. Exogenous methane exerts the therapeutic effects in many organ injury. Our study aims to investigate the potential neuroprotection of methane in a rat model of optic nerve crush (ONC). Adult male Sprague-Dawley rats were subjected to ONC and administrated intraperitoneally with methane-saturated or normal saline (10 ml/kg) once per day for one week after ONC. The retinal ganglion cells (RGCs) density was assessed by hematoxylin and eosin staining and Fluoro-Gold retrogradely labeling. Visual function was evaluated by flash visual evoked potentials (FVEP). The retinal apoptosis was measured by terminal-deoxy-transferase-mediated dUTP nick end labeling (TUNEL) assay and the expression of apoptosis-related factors, such as phosphorylated Bcl-2-associated death promoter (pBAD), phosphorylated glycogen synthase kinase-3ß (pGSK-3ß), Bcl-2 associated X protein (Bax) and Bcl-2 extra large (Bcl-xL). Retinal mitochondrial function was assessed by the mRNA expressions of peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1) and mitochondrial transcription factor A (TFAM), the mitochondrial DNA (mtDNA) copy number, citrate synthase activity and ATP content. Methane treatment significantly improved the RGC loss and visual dysfunction following ONC. As expected, methane also remarkably inhibited the retinal neural apoptosis, such as the fewer TUNEL-positive cells in ganglion cell layer, accompanied by the up-regulations of anti-apoptotic factors (pGSK-3ß, pBAD, Bcl-xL) and the down-regulation of pro-apoptotic factor (Bax). Furthermore, methane treatment suppressed up-regulations of critical mitochondrial components (PGC-1α, NRF1 and TFAM) mRNA and mtDNA copy number, as well as improved the reduction of functional mitochondria markers, including citrate synthase activity and ATP content, in retinas with ONC. Taken together, methane treatment promotes RGC survival and limits retinal mitochondrial dysfunction against ONC insult. Methane can be a potential neuroprotective agent for traumatic and glaucomatous neurodegeneration.

Methane attenuates retinal ischemia/reperfusion injury via anti-oxidative and anti-apoptotic pathways.

Retinal ischemia/reperfusion injury (IRI) may cause incurable visual impairment due to neural regeneration limits. Methane was shown to exert a protective effect against IRI in many organs. This study aims to explore the possible protective effects of methane-rich saline against retinal IRI in rat. Retinal IRI was performed on the right eyes of male Sprague-Dawley rats, which were immediately injected intraperitoneally with methane-saturated saline (25ml/kg). At one week after surgery, the number of retinal ganglion cells (RGCs), total retinal thickness, visual function were measured by hematoxylin and eosin staining, FluoroGold anterograde labeling and flash visual evoked potentials. The levels of 8-hydroxy-2-deoxyguanosine (8-OHdG), 4-Hydroxy-2-nonenal (4-HNE), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), caspase-3, caspase-9, B cell lymphoma/leukemia-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in retinas were assessed by immunofluorescence staining, enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. As expected, methane treatment significantly improved the retinal IRI-induced RGC loss, total retinal layer thinning and visual dysfunction. Moreover, methane treatment significantly reduced the levels of oxidative stress biomarkers (8-OHdG, 4-HNE, MDA) and increased the antioxidant enzyme activities (SOD, CAT, GPx) in the retinas with IRI. Meanwhile, methane treatment significantly increased the anti-apoptotic gene (Bcl-2) expression and decreased the pro-apoptotic gene (Bax) expression, accompanied by the suppression of caspase-3 and caspase-9 activity. Thus, these data demonstrated that methane can exert a neuroprotective role against retinal IRI through anti-oxidative and anti-apoptotic pathways.

Postconditioning with inhaled hydrogen promotes survival of retinal ganglion cells in a rat model of retinal ischemia/reperfusion injury.

Retinal ischemia/reperfusion (I/R) injury plays a crucial role in the pathophysiology of various ocular diseases. Intraperitoneal injection or ocular instillation with hydrogen (H2)-rich saline was recently shown to be neuroprotective in the retina due to its anti-oxidative and anti-inflammatory effects. Our study aims to explore whether postconditioning with inhaled H2 can protect retinal ganglion cells (RGCs) in a rat model of retinal I/R injury. Retinal I/R injury was performed on the right eyes of rats and was followed by inhalation of 67% H2 mixed with 33% oxygen immediately after ischemia for 1h daily for one week. RGC density was counted using haematoxylin and eosin (HE) staining and retrograde labeling with cholera toxin beta (CTB). Visual function was assessed using flash visual evoked potentials (FVEP) and pupillary light reflex (PLR). Potential biomarkers of retinal oxidative stress and inflammatory responses were measured, including the expression of 4-Hydroxynonenalv (4-HNE), interleukin-1 beta (IL1-ß) and tumor necrosis factor alpha (TNF-α). HE and CTB tracing showed that the survival rate of RGCs in the H2-treated group was significantly higher than the rate in the I/R group. Rats with H2 inhalation showed better visual function in assessments of FVEP and PLR. Moreover, H2 treatment significantly decreased the number of 4-HNE-stained cells in the ganglion cell layer and inhibited the retinal overexpression of IL1-ß and TNF-α that was induced by retinal I/R injury. Our results demonstrate that postconditioning with inhaled high-dose H2 appears to confer neuroprotection against retinal I/R injury via anti-oxidative, anti-inflammatory and anti-apoptosis pathways.

Low-dose carbon monoxide inhalation protects neuronal cells from apoptosis after optic nerve crush.

Glaucomatous optic neuropathy, including axonal degeneration and apoptotic death of retinal ganglion cells (RGCs), eventually leads to irreversible visual impairment. Carbon monoxide (CO) acts as a therapeutic agent against neural injury via its anti-apoptotic effect. Here we hypothesized that low-dose CO inhalation can protect RGCs in a rat model of optic nerve crush (ONC). ONC was performed on adult male Sprague Dawley rats to imitate glaucomatous optic damage. Low-dose CO (250 ppm) or air was inhaled for 1 h immediately after ONC, and all the tests were carried out 2 weeks later. Flash visual evoked potentials (FVEP) and pupil light relax (PLR) were recorded for the assessment of visual function. RGC density was evaluated by hematoxylin and eosin staining and Fluorogold labeling. Retinal apoptotic process was assessed by TUNEL staining and caspase-3 activity measurement. Low-dose CO treatment significantly ameliorated the abnormalities of FVEP and PLR induced by ONC. As expected, the RGC density was increased remarkably by CO inhalation after the glaucomatous optic nerve insult. Moreover, CO treatment after ONC significantly decreased the number of TUNEL-positive cells in ganglion cell layer and attenuated the retinal caspase-3 activity. Low-dose CO inhalation protects RGCs from optic nerve injury via inhibiting caspase-3 dependent apoptosis.

Protective effects of methane-rich saline on diabetic retinopathy via anti-inflammation in a streptozotocin-induced diabetic rat model.

As the commonest complication of diabetes mellitus (DM), diabetic retinopathy (DR) is a neuro-vascular disease with chronic inflammatory. Methane could exert potential therapeutic interest in inflammatory pathologies in previous studies. Our study aims to evaluate the protective effects of methane-rich saline on DR and investigate the potential role of related MicroRNA (miRNA) in diabetic rats. Streptozotocin-induced diabetic Sprague-Dawley rats were injected intraperitoneally with methane-rich or normal saline (5 ml/kg) daily for eight weeks. Morphology changes and blood-retinal barrier (BRB) permeability were assessed by hematoxylin eosin staining and Evans blue leakage. Retinal inflammatory cytokines levels of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL1-ß) were evaluated by immunohistochemistry. Retinal protein expressions of glial fibrillary acidic protein (GFAP) and vascular endothelial growth factor (VEGF) were determined by western blotting. Retinal miRNA expressions were examined by miRNA-specific microarray, verified by quantitative RT-PCR and predicted by GO enrichment and KEGG pathway analysis. There was no significant changes in blood glucose level and body weight of diabetic rats with methane-rich or normal saline treatment, but the decreased retinal thickness, retinal ganglial cell loss and BRB breakdown were all significantly suppressed by methane treatment. DM-induced retinal overexpressions of TNF-α, IL-1ß, GFAP and VEGF were also significantly ameliorated. Moreover, the methane treatment significantly up-regulated retinal levels of miR-192-5p (related to apoptosis and tyrosine kinase signaling pathway) and miR-335 (related to proliferation, oxidative stress and leukocyte). Methane exerts protective effect on DR via anti-inflammation, which may be related to the regulatory mechanism of miRNAs.