315 research outputs found
Spatiotemporal evolution and multi-scenario prediction of habitat quality in the Yellow River Basin
IntroductionThe Yellow River Basin (YRB) is not only a vital area for maintaining ecological security but also a key area for China’s economic and social development. Understanding its land-use change trends and habitat quality change patterns is essential for regional ecological conservation and effective resource allocation.MethodsThis study used the patch-generating land-use simulation (PLUS) and Integrated Valuation of Ecosystem Services and Trade-offs (InVEST) models to analyze and predict the spatial and temporal trends of habitat quality in the YRB from 2000 to 2030 under natural development (ND) and ecological conservation and high-quality development (ECD) scenarios. The PLUS model was used to predict land-use change in 2030 under different scenarios, after which the InVEST model was used to obtain the habitat quality distribution characteristics from the 2000–2030 period.Results(1) The mean values of habitat quality in the YRB in 2000, 2010, and 2020 were 0.6849, 0.6992, and 0.7001, respectively. The mean habitat quality values were moderately high. Spatial distribution characteristics were high in the west and low in the east and along the water. In 2030, habitat quality (0.6993) started to decline under ND, whereas under ECD, there was an indication of substantial improvement in habitat quality (0.7186). (2) The mean habitat degradation values in 2000, 2010, and 2020 were 0.0223, 0.0219, and 0.0231, respectively. The level of habitat degradation showed a decreasing trend, followed by an increasing trend with a stable spatial distribution pattern. The mean level of habitat degradation in 2030 (0.0241) continued to increase under ND, while a substantial decrease in the level of habitat degradation occurred under ECD (0.0214), suggesting that the level of habitat degradation could be effectively contained under the ECD scenario. (3) During the study period, the conversion of building land—both negative and positive—had the most pronounced impact on habitat quality per unit area. Further, the conversion of grassland was shown to be a key land transformation that may either lead to the deterioration or improvement of the ecological environment. The results provide scientifific theoretical support and a decision basis for ecological conservation and the high-quality development of the YRB
Testing Lorentz symmetry with space-based gravitational-wave detectors
Lorentz symmetry (LS), one of the most fundamental physical symmetries, has
been extensively studied in the context of quantum gravity and unification
theories. Many of these theories predict a LS violation, which could arise from
the discreteness of spacetime, or extra dimensions. Standard-model extension
(SME) is an effective field theory to describe Lorentz violation whose effects
can be explored using precision instruments such as atomic clocks and
gravitational-wave (GW) detectors. Considering the pure-gravity sector and
matter-gravity coupling sector in the SME, we studied the leading
Lorentz-violating modifications to the time delay of light and the relativistic
frequency shift of the clock in the space-based GW detectors. We found that the
six data streams from the GW mission can construct various combinations of
measurement signals, such as single-arm round-trip path, interference path,
triangular round-trip path, etc. These measurements are sensitive to the
different combinations of SME coefficients and provide novel linear
combinations of SME coefficients different from previous studies. Based on the
orbits of TianQin, LISA, and Taiji missions, we calculated the response of
Lorentz-violating effects on the combinations of the measurement signal data
streams. Our results allow us to estimate the sensitivities for SME
coefficients: for the gravity sector coefficient ,
for matter-gravity coupling coefficients
and , and
for and .Comment: 17 pages, 10 figure
KMT2A promotes melanoma cell growth by targeting hTERT signaling pathway.
Melanoma is an aggressive cutaneous malignancy, illuminating the exact mechanisms and finding novel therapeutic targets are urgently needed. In this study, we identified KMT2A as a potential target, which promoted the growth of human melanoma cells. KMT2A knockdown significantly inhibited cell viability and cell migration and induced apoptosis, whereas KMT2A overexpression effectively promoted cell proliferation in various melanoma cell lines. Further study showed that KMT2A regulated melanoma cell growth by targeting the hTERT-dependent signal pathway. Knockdown of KMT2A markedly inhibited the promoter activity and expression of hTERT, and hTERT overexpression rescued the viability inhibition caused by KMT2A knockdown. Moreover, KMT2A knockdown suppressed tumorsphere formation and the expression of cancer stem cell markers, which was also reversed by hTERT overexpression. In addition, the results from a xenograft mouse model confirmed that KMT2A promoted melanoma growth via hTERT signaling. Finally, analyses of clinical samples demonstrated that the expression of KMT2A and hTERT were positively correlated in melanoma tumor tissues, and KMT2A high expression predicted poor prognosis in melanoma patients. Collectively, our results indicate that KMT2A promotes melanoma growth by activating the hTERT signaling, suggesting that the KMT2A/hTERT signaling pathway may be a potential therapeutic target for melanoma
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Factors Predicting Survival in Patients with Proximal Gastric Carcinoma Involving the Esophagus
AIM:
To investigate the clinicopathologic features which predict surgical overall survival in patients with proximal gastric carcinoma involving the esophagus (PGCE).
METHODS:
Electronic pathology database established in the Department of Pathology of the Nanjing Drum Tower Hospital was searched for consecutive resection cases of proximal gastric carcinoma over the period from May 2004 through July 2009. Each retrieved pathology report was reviewed and the cases with tumors crossing the gastroesophageal junction line were selected as PGCE. Each tumor was re-staged, following the guidelines on esophageal adenocarcinoma, according to the 7th edition of the American Joint Commission on Cancer Staging Manual. All histology slides were studied along with the pathology report for a retrospective analysis of 13 clinicopathologic features, i.e., age, gender, Helicobacter pylori (H. pylori) infection, surgical modality, Siewert type, tumor Bormann's type, size, differentiation, histology type, surgical margin, lymphovascular and perineural invasion, and pathologic stage in relation to survival after surgical resection. Prognostic factors for overall survival were assessed with uni- and multi-variate analyses.
RESULTS:
Patients' mean age was 65 years (range: 47-90 years). The male: female ratio was 3.3. The 1-, 3- and 5-year overall survival rates were 87%, 61% and 32%, respectively. By univariate analysis, age, male gender, H. pylori, tumor Bormann's type, size, histology type, surgical modality, positive surgical margin, lymphovascular invasion, and pT stage were not predictive for overall survival; in contrast, perineural invasion (P = 0.003), poor differentiation (P = 0.0003), > 15 total lymph nodes retrieved (P = 0.008), positive lymph nodes (P = 0.001), and distant metastasis (P = 0.005) predicted poor post-operative overall survival. Celiac axis nodal metastasis was associated with significantly worse overall survival (P = 0.007). By multivariate analysis, ≥ 16 positive nodes (P = 0.018), lymph node ratio > 0.2 (P = 0.003), and overall pathologic stage (P = 0.002) were independent predictors for poor overall survival after resection.
CONCLUSION:
Patients with PGCE showed worse overall survival in elderly, high nodal burden and advanced pathologic stage. This cancer may be more accurately staged as gastric, than esophageal, cancer
Quantum key distribution without alternative measurements and rotations
A quantum key distribution protocol based on entanglement swapping is
proposed. Through choosing particles by twos from the sequence and performing
Bell measurements, two communicators can detect eavesdropping and obtain the
secure key. Because the two particles measured together are selected out
randomly, we need neither alternative measurements nor rotations of the Bell
states to obtain security.Comment: 11 pages, no figures, a modified version of quant-ph/0412014, add a
security proof and delete the identification par
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LNK suppresses interferon signaling in melanoma.
LNK (SH2B3) is a key negative regulator of JAK-STAT signaling which has been extensively studied in malignant hematopoietic diseases. We found that LNK is significantly elevated in cutaneous melanoma; this elevation is correlated with hyperactive signaling of the RAS-RAF-MEK pathway. Elevated LNK enhances cell growth and survival in adverse conditions. Forced expression of LNK inhibits signaling by interferon-STAT1 and suppresses interferon (IFN) induced cell cycle arrest and cell apoptosis. In contrast, silencing LNK expression by either shRNA or CRISPR-Cas9 potentiates the killing effect of IFN. The IFN-LNK signaling is tightly regulated by a negative feedback mechanism; melanoma cells exposed to IFN upregulate expression of LNK to prevent overactivation of this signaling pathway. Our study reveals an unappreciated function of LNK in melanoma and highlights the critical role of the IFN-STAT1-LNK signaling axis in this potentially devastating disease. LNK may be further explored as a potential therapeutic target for melanoma immunotherapy
High throughput 16SrRNA gene sequencing reveals the correlation between Propionibacterium acnes and sarcoidosis
Sequences of the unique OTUs. (XLS 3616 kb
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