Free-electron Driven Terahertz Wave Sources Based on Simth-Purcell Effect

Terahertz electromagnetic wave is one of the hottest research topics in nowadays scientific world thanks to its broad applications in material characterization, medical imaging, wireless communication, and security checking etc. Using free-electron beams to interact with periodic structures via the famous Smith-Purcell effect is an efficient way of generating high-power terahertz radiation. In this chapter, we introduce the basic theory and latest developments of the terahertz radiation schemes using a free-electron beam (including continuous electron beam, a single electron bunch, and a train of electron bunches, etc.) to interact with periodic electromagnetic structures, including grating, surface plasmonics, and subwavelength hole arrays, via a special Smith-Purcell effect or Cherenkov-like effect. A kind of free-electron lasers based on the special Smith-Purcell radiation in the terahertz region is proposed and investigated, which can be developed as high-power terahertz wave sources for practical applications

Role of methyltransferase-like enzyme 3 and methyltransferase-like enzyme 14 in urological cancers

N6-methyladenosine (m6A) modifications can be found in eukaryotic messenger RNA (mRNA), long non-coding RNA (lncRNA), and microRNA (miRNA). Several studies have demonstrated a close relationship between m6A modifications and cancer cells. Methyltransferase-like enzyme 3 (METTL3) and methyltransferase-like enzyme 14 (METTL14) are two major enzymes involved in m6A modifications that play vital roles in various cancers. However, the roles and regulatory mechanisms of METTL3 and METTL14 in urological cancers are largely unknown. In this review, we summarize the current research results for METTL3 and METTL14 and identify potential pathways involving these enzymes in kidney, bladder, prostate, and testicular cancer. We found that METTL3 and METTL14 have different expression patterns in four types of urological cancers. METTL3 is highly expressed in bladder and prostate cancer and plays an oncogenic role on cancer cells; however, its expression and role are opposite in kidney cancer. METTL14 is expressed at low levels in kidney and bladder cancer, where it has a tumor suppressive role. Low METTL3 or METTL14 expression in cancer cells negatively regulates cell growth-related pathways (e.g., mTOR, EMT, and P2XR6) but positively regulates cell death-related pathways (e.g., P53, PTEN, and Notch1). When METTL3 is highly expressed, it positively regulates the NF-kB and SHH-GL1pathways but negatively regulates PTEN. These results suggest that although METTL3 and METTL14 have different expression levels and regulatory mechanisms in urological cancers, they control cancer cell fate via cell growth- and cell death-related pathways. These findings suggest that m6A modification may be a potential new therapeutic target in urological cancer

Coffee consumption and risk of prostate cancer: a systematic review and meta-analysis

Objectives To conduct a systematic review with meta-analysis of cohort studies to evaluate the association of coffee consumption with the risk of prostate cancer.Data sources PubMed, Web of Science and Embase were searched for eligible studies up to September 2020.Study selection Cohort studies were included.Data extraction and synthesis Two researchers independently reviewed the studies and extracted the data. Data synthesis was performed via systematic review and meta-analysis of eligible cohort studies. Meta-analysis was performed with the “metan” and “glst” commands in Stata 14.0.Main outcomes and measures Prostate cancer was the main outcome. It was classified as localised prostate cancer which included localised or non-aggressive cancers; advanced prostate cancer which included advanced or aggressive cancers; or fatal prostate cancer which included fatal/lethal cancers or prostate cancer-specific deaths.Results Sixteen prospective cohort studies were finally included, with 57 732 cases of prostate cancer and 1 081 586 total cohort members. Higher coffee consumption was significantly associated with a lower risk of prostate cancer. Compared with the lowest category of coffee consumption, the pooled relative risk (RR) was 0.91 (95% CI 0.84 to 0.98), I2= 53.2%) for the highest category of coffee consumption. There was a significant linear trend for the association (p=0.006 for linear trend), with a pooled RR of 0.988 (95% CI 0.981 to 0.995) for each increment of one cup of coffee per day. For localised, advanced and fatal prostate cancer, the pooled RRs were 0.93 (95% CI 0.87 to 0.99), 0.88 (95% CI 0.71 to 1.09) and 0.84 (95% CI 0.66 to 1.08), respectively. No evidence of publication bias was indicated in this meta-analysis.Conclusions This study suggests that a higher intake of coffee may be associated with a lower risk of prostate cancer

Short-Term Outcomes of Three-Port Laparoscopic Right Hemicolectomy Versus Five-Port Laparoscopic Right Hemicolectomy: With a Propensity Score Matching Analysis

Purpose: The aim of this study is to compare the short-term and pathological outcomes of TPLRC (Three-port laparoscopic right hemicolectomy) and FPLRC (Five-port laparoscopic right hemicolectomy), using propensity score matching analysis. Methods: One hundred and sixty-eight patients who accepted laparoscopic right hemicolectomy with either three ports or five ports from January 2013 to October 2017 were non-randomly selected and analyzed retrospectively. Propensity score matching model was used to eliminate the patients’ selection bias between two groups. Results: A total of 168 patients were involved. After propensity score matching, 39 for each group were compared. The number of harvested lymph nodes was significantly larger in the TPLRC group than in the FPLRC group (18.36 ± 8.58 vs. 14.90 ± 6.63, p = 0.048). A lower mean operative time was observed in the TPLRC group (136.24 ± 26.78 vs. 168.64 ± 43.68 min, p < 0.001). A less blood loss in the TPLRC group (62.44 ± 55.17, 135.54 ± 139.11 ml, p = 0.003). No significant differences in the other short-term outcomes between the two groups. Conclusions: TPLRC is a safe and feasible surgical procedure with similar results of FPLRC in short-term clinical outcomes. TPLRC has the advantages of shorter operative time, less blood loss and larger number of harvested lymph nodes. A randomized prospective clinical trial of long-term outcomes of TPLRC is required to further prove the present results

Effect of heavy metals in mixed domestic-industrial wastewater on performance of recirculating standing hybrid constructed wetlands (RSHCWs) and their removal

Heavy metals (HMs) are frequently detected in wastewaters, especially in industrial discharges or mixed domestic-industrial drainage. Constructed wetlands (CWs) are effective means for the treatment of decentralized wastewater and recirculating standing hybrid constructed wetlands (RSHCWs) provide aerobic conditions for the removal of both nutrients and organic matter. However, their effectiveness regarding HM removal and the effects of HM stress on the performance of RSHCWs remain unclear. The present study examined three types of substrates in RSHCWs with varying HM inflow loads with the aim to evaluate their potential and underlying mechanisms for the removal of HMs from simulated mixed wastewater. The results indicate that HM removal exceeded 85% at 24 h of treatment, and a high inflow load (202-259 mg.m(-2).d(-1)) achieved high removal. HMs mainly accumulated in the substrate (91.0-98.3%), and RSHCWs filled with lava rock and gravel provided higher removal efficiencies of Cd than bio-ceramic at 24 h of treatment. Although plants were minor sinks for HM removal, HMs accumulated in Canna indica L. (grown in RSHCWs) with high bioconcentration factors and translocation factors. RSHCWs quickly co-precipitated HMs in mixed wastewater and decreased their toxicity on plants and microorganisms. Consequently, they achieved consistent and effective removal of total nitrogen, total phosphorus, and organic matter. These findings are useful for the design of CWs (such as RSHCWs) for the treatment of mixed wastewater discharged from both rural and urban areas with fluctuating HM stress