Method for rock fracture prediction and early warning: Insight from fusion of multi-physics field information.

Understanding the precursors leading to rock fracture is crucial for ensuring safety in mining and geotechnical engineering projects. To effectively discern these precursors, a collaborative monitoring approach that integrates multiple sources of information is imperative. This paper considered a rock multi-parameter monitoring loading system, incorporating infrared radiation and acoustic emission monitoring technologies to simultaneously track the rock fracture process. The study delves into the spatiotemporal evolution patterns of infrared radiation and acoustic emission in rock under loading. Utilizing stress, cumulative acoustic emission count, and average infrared radiation temperature (AIRT), the paper establishes a comprehensive evaluation model termed "acoustic-thermal-stress" fusion information, employing principal component analysis (PCA). The research reveals that the sensitivity to rock sample damage response follows the sequence of cumulative acoustic emission count, AIRT, and stress. Furthermore, a novel method for identifying rock fracture precursors is proposed, based on the first derivative of the comprehensive evaluation model. This method addresses the limitations of single physical field information, enhancing the robustness of monitoring data. It determines the average stress level of fracture precursors to be 0.77σmax. Subsequently, the study defines the probability function of rock damage during loading and fracture, enabling the realization of probability-based warnings for rock fracture. This approach introduces a new perspective on rock fracture prediction, significantly contributing to safety monitoring and warning systems in mine safety and geotechnical engineering. The findings of this research hold paramount engineering significance, offering valuable insights for enhancing safety measures in such projects.

Preventive effects of chemical drugs on recurrence of colorectal adenomas: systematic review and Bayesian network meta-analysis.

BACKGROUND: The onset of colorectal adenomas (CRAs) is significantly associated with colorectal cancer. The preventive effects of chemical drugs on the recurrence of CRAs have been evaluated in a large number of randomized controlled trials (RCTs). However, there are still uncertainties about the relative effectiveness of such chemical drugs. METHODS: We searched relevant RCTs published in six databases up to February 2023. The quality of the included studies was assessed by using the Cochrane risk of bias assessment tool and Review Manager 5.4. Pairwise comparison and network meta-analysis (NMA) were conducted using RStudio to compare the effects of chemical drugs on the recurrence of CRAs. RESULTS: Forty-five high-quality RCTs were included. A total of 35 590 (test group: 20 822; control group: 14 768) subjects with a history of CRAs have been enrolled and randomized to receive placebo treatment or one of 24 interventions. Based on surface under the cumulative ranking values and NMA results, difluoromethylornithine (DFMO) + Sulindac significantly reduced the recurrence of CRAs, followed by berberine and nonsteroidal antiinflammatory drugs. CONCLUSION: DFMO + Sulindac is more effective in reducing the recurrence of CRAs but has a high risk of adverse events. Considering drug safety, tolerance, and compliance, berberine has a brighter prospect of clinical development. However, further studies are needed to verify our findings.

Oncologic outcomes of watch-and-wait strategy or surgery for low to intermediate rectal cancer in clinical complete remission after adjuvant chemotherapy: a systematic review and meta-analysis.

BACKGROUND: A watch-and-wait (WW) strategy or surgery for low to intermediate rectal cancer that has reached clinical complete remission (cCR) after neoadjuvant chemotherapy (nCRT) or total neoadjuvant therapy (TNT) has been widely used in the clinic, but both treatment strategies are controversial. OBJECTIVE: The aim of this study was to compare the oncologic outcomes of a watch-and-wait strategy or a surgical approach to treat rectal cancer in complete remission and to report the evidence-based clinical advantages of the two treatment strategies. METHODS: Seven national and international databases were searched for clinical trials comparing the watch-and-wait strategy with surgical treatment for oncological outcomes in patients with rectal cancer in clinical complete remission. RESULTS: In terms of oncological outcomes, there was no significant difference between the watch-and-wait strategy and surgical treatment in terms of overall survival (OS) (HR = 0.92, 95% CI (0.52, 1.64), P = 0.777), and subgroup analysis showed no significant difference in 5-year disease-free survival (5-year DFS) between WW and both local excision (LE) and radical surgery (RS) (HR = 1.76, 95% CI (0.97, 3.19), P = 0.279; HR = 1.98, 95% CI (0.95, 4.13), P = 0.164), in distant metastasis rate (RR = 1.12, 95% CI (0.73, 1.72), P = 0.593), mortality rate (RR = 1.62, 95% CI (0.93, 2.84), P = 0.09), and organ preservation rate (RR = 1.05, 95% CI (0.94, 1.17), P = 0.394) which were not statistically significant and on the outcome indicators of local recurrence rate (RR = 2.09, 95% CI (1.44, 3.03), P < 0.001) and stoma rate (RR = 0.35, 95% CI (0.20, 0.61), P < 0.001). There were significant differences between the WW group and the surgical treatment group. CONCLUSION: There were no differences in OS, 5-year DFS, distant metastasis, and mortality between the WW strategy group and the surgical treatment group. The WW strategy did not increase the risk of local recurrence compared with local resection but may be at greater risk of local recurrence compared with radical surgery, and the WW group was significantly better than the surgical group in terms of stoma rate; the WW strategy was evidently superior in preserving organ integrity compared to radical excision. Consequently, for patients who exhibit a profound inclination towards organ preservation and the evasion of stoma formation in the scenario of clinically complete remission of rectal cancer, the WW strategy can be contemplated as a pragmatic alternative to surgical interventions. It is, however, paramount to emphasize that the deployment of such a strategy should be meticulously undertaken within the ambit of a multidisciplinary team's management and within specialized centers dedicated to rectal cancer management.

Surgical, oncological, and functional outcomes of local and radical resection after neoadjuvant chemotherapy or chemoradiotherapy for early- and mid-stage rectal cancer: a systematic review and meta-analysis.

BACKGROUND: Radical resection is typically the standard treatment for early- and mid-stage rectal cancer as local resection may result in a high rate of recurrence and risk of distant metastasis. A growing number of studies have shown that local excision after neoadjuvant chemotherapy or chemoradiotherapy can significantly reduce recurrence rates and is a feasible strategy to preserve the rectum as an alternative to conventional radical resection. OBJECTIVE: This study aims to compare the efficacy of local resection after neoadjuvant chemotherapy or chemoradiotherapy with radical surgery for early- and mid-stage rectal cancer and to report the evidence-based clinical advantages of both techniques. METHODS: Clinical trials comparing oncologic and perioperative outcomes of local and radical resection after neoadjuvant chemotherapy or chemoradiotherapy in patients with early- to mid-stage rectal cancer were searched in PubMed, Embase, Web Of Science, and Cochrane databases, and a total of 5 randomized controlled trials and 11 cohort study trials were included. RESULTS: In terms of oncology and perioperative outcomes, there were no statistically significant differences between the radical resection group and the local resection group in terms of OS [HR = 0.99, 95%CI (0.85, 1.15), p = 0.858], DFS [HR = 1.01, 95%CI (0.64, 1.58), p = 0.967], distant metastasis rate [RR = 0.76, 95%CI (0.36,1.59), p = 0.464], and local recurrence rate [RR = 1.30, 95%CI (0.69, 2.47), p = 0.420]. However, there were significant differences in the outcomes of complications [RR = 0.49, 95% CI (0.33, 0.72), p < 0.001], length of hospital stays [WMD = - 5.13, 95%CI (- 6.22, - 4.05), p < 0.001], enterostomy [RR = 0.13, 95%CI (0.05, 0.37), p < 0.001], operative time [- 94.31, 95%CI (- 117.26, - 71.35), p < 0.001], and emotional functioning score [WMD = 2.34, 95% CI (0.94, 3.74), p < 0.001]. CONCLUSION: Local resection after neoadjuvant chemotherapy or chemoradiotherapy may be an effective alternative to radical surgery in patients with early and middle rectal cancer.

Ruthenium Carbene-Mediated Construction of Strained Allenes via the Enyne Cross-Metathesis/Cyclopropanation of 1,6-Enynes.

Herein, we report on the unprecedented dimerization of 1,6-enynes using a commercially available ruthenium complex RuCl2(PPh3)3, which results in a series of bicyclo[3.1.0]hexyl allene derivatives in moderate to excellent yields. Mechanistic investigation indicates that the in-situ-generated ruthenium vinylidene undergoes a site-selective metathesis process to provide allenyl ruthenium carbene, which can be intramolecularly trapped by the pendent C=C bond of enyne through a [2 + 2] cycloaddition/metal elimination process.

Corrigendum: Comparative Description of Magnetic Interactions in Sr2CuTeO6 and Sr2CuWO6 (2017 J. Phys.: Condens. Matter 29 105801).

Typographical errors are present in the Table 2 of the paper stated above. The correct table is give below. All numerical results and conclusions of the paper remains unchanged.

Comparative description of magnetic interactions in Sr2CuTeO6 and Sr2CuWO6.

In this work, we comparatively explored the electronic structure and the low-dimensional magnetic interactions of double-perovskite compounds Sr2CuTeO6 and Sr2CuWO6 through first-principles calculations. The electronic structure calculations indicate that the Cu2+ (3d 9) site is the only magnetic active one, whereas Te6+ and W6+ remain in nonmagnetic states with d 10 and d 0 electronic configurations, respectively. The magnetic exchange interactions have been evaluated on the basis of the classical Heisenberg model. Both Sr2CuTeO6 and Sr2CuWO6 should be strong frustrated 2D magnetism, in excellent agreement with the experimental observations. Nevertheless, the nearest-neighbor antiferromagnetic interaction J 1 plays a determined role in constructing the Néel antiferromagnetic ordering within the square Cu2+ framework of Sr2CuTeO6. While, the next-nearest-neighbor antiferromagnetic interaction J 2 transcends the nearest-neighbor interaction J 1, establishes the collinear antiferromagnetic ordering in Sr2CuWO6. The discrimination has been explored and analyzed in detail using density of states, charge density as well as spin density analysis.