Investigation and Application of High Megavoltage X-Ray Imaging Mode in Radiotherapy

After drawbacks and shortages of using conventional kV or MV imaging mode were analyzed, this study proposes a new position verification mode with using the energy larger than 15 MeV or nominal accelerating potential greater than 25 MV X-Ray. The new position verification mode is named HMV imaging mode. Along with the comparison of theoretical analyses, phantom experiments and clinical results to the original imaging modes, this report is going to demonstrate the HMV imaging mode is superior to traditional kV and MV imaging modes. This report first theoretically analyzed three main effects of X-ray interacting with medium by numerous equations and compared their mass attenuation coefficient with different types of tissue. X-ray irradiated on a “Catphan 500” cylinder phantom with different energies to verify these theoretical results. Furthermore, based on phantom experiments’ results, we have done numerous clinical trials and comparisons with patient’s clinical results. The theoretical and experimental results illustrate that the scanned images from HMV mode have a good quality and have ability to identify different tissue components clearly. HMV imaging mode overcomes drawbacks of position verification from both kV and MV level imaging mode as well as keeping advantages of kV and MV imaging mode. The result indicates that HMV is a good position verification mode in radiotherapy.

Level of circulating PD-L1 expression in patients with advanced gastric cancer and its clinical implications

Objective：The programmed cell death-1 receptor/programmed cell death-1 ligand （PD-1/PD-L1） pathway plays a crucial role in tumor evasion from host immunity.This study was designed to evaluate the association between circulating PD-L1 expression and prognosis in patients with advanced gastric cancer.Methods：Totally 80 advanced gastric cancer patients and 40 health controls from Beijing Cancer Hospital were enrolled in the present study.Circulating PD-L1 expression was tested by enzymelinked immunosorbent assay （ELISA）.The associations between the expression level of PD-L1 and clinicopathological features and prognosis were analyzed statistically.Results：Expression of PD-L1 in advanced gastric cancer patients was significandy up-regulated compared with health people （P=0.006）.The expression of PD-L1 was significantly correlated with differentiation and lymph node metastasis （P=0.026 and P=0.041,respectively）.Although we didn＇t find significant difference in all advanced gastric cancer patients with different PD-L1 expression,the adenocarcinoma patients with higher up-regulated PD-L1 expression had much better prognosis than low expression patients （65.6％ vs.44.7％,P=0.028）.Conclusions：PD-L1 was elevated in advance gastric cancer patients and may play an important role in tumor immune evasion and patients prognosis.

Construction and external validation of a nomogram that predicts lymph node metastasis in early gastric cancer patients using preoperative parameters

Objective: To create a nomogram to predict the incidence of lymph node metastasis(LNM) in early gastric cancer(EGC) patients and to externally validate the nomogram.Methods: To construct the nomogram,we retrospectively analyzed a primary cohort of 272 EGC patients.Univariate analysis and a binary logistic regression were performed.A nomogram predicting the incidence of LNM in EGC patients was created.The discrimination ability of the nomogram was measured using the concordance index(c-index),and the nomogram was also calibrated.Then,another prospective cohort of 81 patients was analyzed to validate the nomogram.Results: In the primary cohort,LNM was pathologically confirmed in 37(13.6%) patients.In multivariate analysis,the presence of an ulcer,the maximum lesion diameter observed via gastroscopy,the thickness of the lesion observed via endoscopic ultrasonography,and the presence of enlarged lymph nodes on computed tomography(CT) were independent risk factors for LNM.A nomogram was then created based on the regression model with the c-index of 0.905,and the calibration curve of the nomogram fell approximately on the ideal 45-degree line.The cut-off score of the nomogram was 110,and the sensitivity,specificity,positive predictive and negative predictive values of the nomogram in the primary cohort were 81.1%,86.0%,47.6% and 96.7%,respectively,and in the prospective validation cohort were 75.0%,91.0%,60.0% and 95.5%,respectively.The calibration curve of the external validation cohort was almost on the 45-degree line.Conclusions: We developed an effective nomogram predicting the incidence of LNM for EGC patients.

Oxaliplatin plus S-1 or capecitabine as neoadjuvant or adjuvant chemotherapy for locally advanced gastric cancer with D2lymphadenectomy: 5-year follow-up results of a phase II-III randomized trial

Objective： To compare the effect of neoadjuvant chemotherapy （NACT） with adjuvant chemotherapy （ACT） using oxaliplatin plus S-1 （sex） or capecitabine （CapeOX） on gastric cancer patients with D2 lymphadenectomy. Methods： This was a two-by-two factorial randomized phase Ⅱ-Ⅲ trial, and registered on ISRCTN registry （No. ISRCTN12206108）. Locally advanced gastric cancer patients were randomized to neoadjuvant sex, neoadjuvant CapeOX, adjuvant sex, or adjuvant CapeOX arms. Primary analysis was performed on an intention- to-treat （ITT） basis using overall survival （OS） as primary endpoint. Results： This trial started in September 2011 and closed in December 2012 with 100 patients enrolled. Treatment completion rate was 56%, 52%, 38% and 30% in the four arms, respectively. NACT group had fewer dropouts due to unacceptable toxicity （P=0.042）. Surgical complication rate did not differ by the four groups （P=0.986）. No survival signifcant difference was found comparing NACT with ACT （P=0.664; 5-year-OS： 70% vs. 74% respectively）, nor between the sex and CapeOX groups （P=0.252; 5-year-OS： 78% vs. 66% respectively）. Subgroup analysis showed sex significantly improved survival in patents with diffuse type （P=0.048）. Conclusions： No significant survival difference was found between NACT and ACT. sex and CapeOX had good safety and efficacy as neoadjuvant regimens. Diffuse type patients may survive longer due to sex.

Clinicopathological and prognostic differences between mucinous gastric carcinoma and signet-ring cell carcinoma

Objective： To analyze the differences in clinicopathologic characteristics and prognosis between mucinous gastric carcinoma （MGC） and signet-ring cell carcinoma （SRCC）. Methods： Clinicopathologic and prognostic data of 1,637 patients with histologically confirmed MGC or SRCC who received surgical operations in the Department of Gastroenterological Surgery, Beijing Cancer Hospital between December 2004 and December 2009 were retrospectively collected and analyzed. The clinicopathological features were analyzed statistically using Z2 test. Survival was analyzed using the Kaplan- Meier method and multivariate analysis of Cox proportional hazards regression model （backward, stepwise）. Results： A total of 181 patients with gastric cancer （74 MGC, 107 SRCC） were included. MGC, when compared with SRCC, was featured by senile patients, stage III and I~, upper third stomach, large tumor size, positive lymph node metastasis, and positive lymphatic vascular invasion （P〈0.05）. The overall 5-year survival rate showed no difference between the two groups （48.8% vs. 44.8%, P〉0.05）. However, the survival rate for MGC patients was significant lower than that for SRCC patients when compared among the age 〈60 years, negative distant metastasis, and tumor localized at upper third stomach （P〈0.05）. Multivariate Cox proportional hazards models revealed that distant metastasis was a significant independent prognostic indicator in MGC group, and lymph node metastasis and distant metastasis was significant independent prognostic indicators in SRCC group. Conclusions： While compared with SRCC, MGC is associated with a more aggressive tumor biologic behavior. There is no statistically significant difference in distant metastasis, an independent prognostic indicator for both MGC and SRCC, which might be the reason for no significant difference of the overall survival rate between the patients with MGC and SRCC.

Nomogram for predicting lymph node metastasis rate of submucosal gastric cancer by analyzing clinicopathological characteristics associated with lymph node metastasis

Background： To combine dinicopathological characteristics associated with lymph node metastasis for submucosal gastric cancer into a nomogram. Methods： We retrospectively analyzed 262 patients with submucosal gastric cancer who underwent D2 gastrectomy between 1996 and 2012. The relationship between lymph node metastasis and clinicopathological features was statistically analyzed. With multivariate logistic regression analysis, we made a nomogram to predict the possibility of lymph node metastasis. Receiver operating characteristic （ROC） analysis was also performed to assess the predictive value of the model. Discrimination and calibration were performed using internal validation. Results： A total number of 48 （18.3%） patients with submucosal gastric cancer have pathologically lymph node metastasis. For submucosal gastric carcinoma, lymph node metastasis was associated with age, tumor location, macroscopic type, size, differentiation, histology, the existence of ulcer and lymphovascular invasion in univariate analysis （all P〈0.05）. The multivariate logistic old, macroscopic type III or mixed, undifferentiated type, regression analysis identified that age _〈50 years and presence of lymphovascular invasion were independent risk factors of lymph node metastasis in submucosal gastric cancer （all P〈0.05）. We constructed a predicting nomogram with all these factors for lymph node metastasis in submucosal gastric cancer with good discrimination [area under the curve （AUC） =0.844]. Internal validation demonstrated a good discrimination power that the actual probability corresponds closely with the predicted probability. Conclusions： We developed a nomogram to predict the rate of lymph node metastasis for submucosal gastric cancer. With good discrimination and internal validation, the nomogram improved individualized predictions for assisting clinicians to make appropriated treatment decision for submucosal gastric cancer patients.

Exploration and optimization of surgical techniques for laparoscopic transhiatal lower mediastinal lymph node dissection for adenocarcinoma of esophagogastric junction: A prospective IDEAL 2a study with qualitative design

Objective: To explore the change and feasibility of surgical techniques of laparoscopic transhiatal(TH)-lower mediastinal lymph node dissection(LMLND) for adenocarcinoma of the esophagogastric junction(AEG)according to Idea, Development, Exploration, Assessment, and Long-term follow-up(IDEAL) 2a standards.Methods: Patients diagnosed with AEG who underwent laparoscopic TH-LMLND were prospectively included from April 14, 2020, to March 26, 2021. Clinical and pathological information as well as surgical outcomes were quantitatively analyzed. Semistructured interviews with the surgeon after each operation were qualitatively analyzed.Results: Thirty-five patients were included. There were no cases of transition to open surgery, but three cases involved combination with transthoracic surgery. In qualitative analysis, 108 items under three main themes were detected: explosion, dissection, and reconstruction. Revised instruction was subsequently designed according to the change in surgical technique and the cognitive process behind it. Three patients had anastomotic leaks postoperatively, with one classified as Clavien-Dindo Ⅲa.Conclusions: The surgical technique of laparoscopic TH-LMLND is stable and feasible;further IDEAL 2b research is warranted.

Germline mutations in hereditary diffuse gastric cancer

Gastric cancer is one of the leading causes of cancer-related deaths worldwide. Among which, about 1%–3% of gastric cancer patients were characterized by inherited gastric cancer predisposition syndromes, knowing as hereditary diffuse gastric cancer（HDGC）. Studies reported that CDH1 germline mutations are the main cause of HDGC. With the help of rapid development of genetic testing technologies and data analysis tools, more and more researchers focus on seeking candidate susceptibility genes for hereditary cancer syndromes. In addition, National Comprehensive Cancer Network（NCCN） guidelines recommend that the patients of HDGC carrying CDH1 mutations should undergo prophylactic gastrectomy or routine endoscopic surveillances. Therefore, genetic counseling plays a key role in helping individuals with pathogenic mutations make appropriate risk management plans. Moreover, experienced and professional genetic counselors as well as a systematic multidisciplinary team（MDT） are also required to facilitate the development of genetic counseling and benefit pathogenic mutation carriers who are in need of regular and standardized risk management solutions. In this review, we provided an overview about the germline mutations of several genes identified in HDGC, suggesting that these genes may potentially act as susceptibility genes for this malignant cancer syndrome. Furthermore, we introduced information for prevention, diagnosis and risk management of HDGC. Investigations on key factors that may have effect on risk management decision-making and genetic data collection of more cancer syndrome family pedigrees are required for the development of HDGC therapeutic strategies.

Utilizing local anti-cancer treatment and online medical service during the COVID-19 pandemic

Since the first outbreak of the coronavirus disease(COVID-19)in the winter of 2019,this pandemic has resulted in significant global social and economic disruption,as well as global public health and medical crises[1].Climate,weather conditions,and even latitude have now been acknowledged to be directly associated with COVID-19 outbreaks[2-4].It was reported that 60%of the confirmed cases of COVID-19 occurred in areas where the air temperature ranged from 5℃to 15℃[4].These earlier research results strongly implied that the COVID-19 pandemic might spread cyclically and outbreaks might recur in large cities in the mid-latitudes(for example,the northern part of China)in autumn 2020[4],which has now been confirmed by the third wave of the pandemic.With quarantines and other restrictive legislations and control measures being put in action to contain the spread of the disease[5],the pandemic has also manifested additional obstacles in the treatment of other diseases.For example,a median dose delay of 14(6-20)days was found in patients who received one cycle of gastric chemotherapy in our department from the first outbreak till the spring festival of 2020(n=79).

Genomic characterization of peritoneal lavage cytology-positive gastric cancer

Objective: Positive peritoneal lavege cytology(CY1) gastric cancer is featured by dismal prognosis, with high risks of peritoneal metastasis. However, there is a lack of evidence on pathogenic mechanism and signature of CY1and there is a continuous debate on CY1 therapy. Therefore, exploring the mechanism of CY1 is crucial for treatment strategies and targets for CY1 gastric cancer.Methods: In order to figure out specific driver genes and marker genes of CY1 gastric cancer, and ultimately offer clues for potential marker and risk assessment of CY1, 17 cytology-positive gastric cancer patients and 31matched cytology-negative gastric cancer patients were enrolled in this study. The enrollment criteria were based on the results of diagnostic laparoscopy staging and cytology inspection of exfoliated cells. Whole exome sequencing was then performed on tumor samples to evaluate genomic characterization of cytology-positive gastric cancer.Results: Least absolute shrinkage and selection operator(LASSO) algorithm identified 43 cytology-positive marker genes, while Mut Sig CV identified 42 cytology-positive specific driver genes. CD3G and CDKL2 were both driver and marker genes of CY1. Regarding mutational signatures, driver gene mutation and tumor subclone architecture, no significant differences were observed between CY1 and negative peritoneal lavege cytology(CY0).Conclusions: There might not be distinct differences between CY1 and CY0, and CY1 might represent the progression of CY0 gastric cancer rather than constituting an independent subtype. This genomic analysis will thus provide key molecular insights into CY1, which may have a direct effect on treatment recommendations for CY1and CY0 patients, and provides opportunities for genome-guided clinical trials and drug development.

An envelope-based machine learning workflow for locating earthquakes in the southern Sichuan Basin

The development of machine learning technology enables more robust real-time earthquake monitoring through automated implementations. However, the application of machine learning to earthquake location problems faces challenges in regions with limited available training data. To address the issues of sparse event distribution and inaccurate ground truth in historical seismic datasets, we expand the training dataset by using a large number of synthetic envelopes that closely resemble real data and build an earthquake location model named ENVloc. We propose an envelope-based machine learning workflow for simultaneously determining earthquake location and origin time. The method eliminates the need for phase picking and avoids the accumulation of location errors resulting from inaccurate picking results. In practical application, ENVloc is applied to several data intercepted at different starting points. We take the starting point of the time window corresponding to the highest prediction probability value as the origin time and save the predicted result as the earthquake location. We apply ENVloc to observed data acquired in the southern Sichuan Basin, China, between September 2018 and March 2019. The results show that the average difference with the catalog in latitude, longitude, depth, and origin time is 0.02°,0.02°, 2 km, and 1.25 s, respectively. These suggest that our envelope-based method provides an efficient and robust way to locate earthquakes without phase picking, and can be used in earthquake monitoring in near-real time.

腹腔化疗港在胃癌腹膜转移中应用的安全性分析

目的:腹腔化疗可将药物直接作用于腹膜转移病灶,正逐渐被应用于胃癌腹膜转移的治疗。通过腹腔化疗港可反复多次进行腹腔化疗,而化疗港的顺利使用是腹腔化疗持续进行的关键。本研究将探讨在胃癌腹膜转移患者留置腹腔化疗港的安全性。方法:回顾性分析2015年6月至2018年6月于北京大学肿瘤医院行腹腔化疗港留置术患者的临床资料,分析腹腔化疗港在胃癌腹膜转移中应用的过程、注意事项及安全性,探讨并发症发生原因及预防处理方式。结果:共有54例患者植入55个化疗港,平均使用时间为8.4(0.8～32.0)个月,共13例出现并发症(23.6%),发生率从高到低依次为堵塞(7.3%)、严重疼痛(5.5%)、感染(3.6%)、反流(3.6%)、置针困难(1.8%)及皮下硬结(1.8%)。并发症发生的中位时间为化疗港放置后2.1个月。分析未发现与并发症相关的高危因素(P>0.05)。结论:通过规范与细致的操作,腹腔化疗港在胃癌腹膜转移中的应用安全可行。

LGR5 is a promising biomarker for patients with stage Ⅰ and Ⅱ gastric cancer

Objective： To investigate Leucine-rich repeat-containing G protein-coupled receptor 5 （LGR5） expressions in gastric cancer and to evaluate its clinical significance. Methods： LGR5 expression was assessed by immunohistochemistry in 257 gastric cancer patients after surgery. The relationships between LGR5 expression and clinicopathological features and patients prognosis were statistically analyzed. Results： The expression of LGR5 was significantly higher in gastric cancers as a cancer stem cell marker than in adjacent normal tissues （P〈0.001）, and more frequently in patients with intestinal type, well-moderate differentiation and stage I and II （P〈0.05）. Although we found gastric cancer patients with LGR5 positive expression had a poorer prognosis, it didn＇t meet statistical significance （P〉0.05）. LGR5 negative expression was significantly related to the favorable overall survival in stage I and II gastric cancer patients （P〈0.05）. Furthermore, patients with high LGR5 expression tended to be more likely to get progression and have poorer progress-free survival （P〈0.05）. Multivariate Cox regression analysis revealed that LGR5 expression was an independent factor of overall survival for the patients with stage I and II gastric cancer （P〈0.05）. Conclusions： Our results show that LGR5 may play an important role in tumorigenesis and progression and would be a powerful marker to predict the prognosis of patients with stage I and II gastric cancer.

Depth of tumor invasion and tumor-occupied portions of stomach are predictive factors of intra-abdominal metastasis

Objective： Diagnostic laparoscopy is recommended for the pretherapeutic staging of gastric cancer to detect any unexpected or unconfirmed intra-abdominal metastasis. The aim of this study was to evaluate the role and indications of diagnostic laparoscopy in the detection of intra-abdominal metastasis. Methods： Standard diagnostic laparoscopy with peritoneal cytology examination was performed prospectively on patients who were clinically diagnosed with primary local advanced gastric cancer （CT≥2M0）. We calculated the rate of intra-abdominal metastases identified by diagnostic laparoscopy, and examined the relationship between peritoneal dissemination （P） and cytology results （CY）. Split-sample method was applied to find clinical risk factors for intra-abdominal metastasis. Multivariate logistic regression analysis and receiver-operator characteristic （ROC） analysis were performed in training set to find out risk factors ofintra-abdominal metastasis, and then validate it in testing set. Results： Out of 249 cM0 patients, 51 （20.5%） patients with intra-abdominal metastasis were identified by diagnostic laparoscopy, including 20 （8.0%） P1CY1, 17 （6.8%） POCY1 and 14 （5.6%） P1CY0 patients. In the training set, multivariate logistic regression analysis and ROC analysis showed that the depth of tumor invasion on computer tomography （CT） scan ≥21 mm and tumor-occupied 〉2 portions of stomach are predictive factors of metastasis. In the testing set, when diagnostic laparoscopy was performed on patients who had one or two of these risk factors, the sensitivity and positive predictive value for detecting intra-abdominal metastasis were 90.0% and 32.1%, respectively. Conclusions： According to our results, depth of tumor invasion and tumor-occupied portions of stomach are predictive factors ofintra-abdominal metastasis.

Prognostic role of lymph node metastasis in early gastric cancer

Objective： To clarify the relationship between clinicopathological features and lymph node metastasis and to propose the potential indications of lymph node metastasis for prognosis in early gaswic cancer （EGC） patients. Methods： We retrospectively observed 226 EGC patients with lymph node resection, and analyzed the associations between lymph node metastasis and clinicopathological parameters using the chi-square test in univariate analysis and logistic regression analysis in multivariate analysis. Overall survival analysis was determined using the Kaplan-Meier and log-rank test. We conducted multivariate prognosis analysis using the Cox proportional hazards model. Results： Of all the EGC patients, 7.5% （17/226） were histologically shown to have lymph node metastasis. The differentiation, lymphovascular invasion and depth of invasion were independent risk factors for lymph node metastasis in EGC. The 5- and 10-year survival rates were significantly lower in patients with lymph node metastasis than in those without and the patients also had shorter progress-free survival time. Lymph node metastasis and tumor size were independent prognostic factors for EGC. The status of the lymph nodes was a significant factor in predicting recurrence or metastasis after surgery. Conclusions： The undifferentiated carcinoma and lymphovascular and/or submucosal invasion were associated with a higher incidence of lymph node metastasis in EGC patients, whom need to perform subsequent D2 lymphadenectomy or laparoscopic lymph node dissection and more rigorous follow-up or additional chemotherapy/radiation after D2 gastrectomy for poor prognosis and high recurrence/metastasis rate.

Laparoscopic vs.open lower mediastinal lymphadenectomy for Siewert typeⅡ/Ⅲadenocarcinoma of esophagogastric junction:An exploratory,observational,prospective,IDEAL stage2b cohort study(CLASS-10 study)

Objective:This study aims to verify the feasibility and efficacy of laparoscopic lower mediastinal lymphadenectomy for Siewert typeⅡ/Ⅲadenocarcinoma of esophagogastric junction(AEG).Setting:An exploratory,observational,prospective,cohort study will be carried out under the Idea,Development,Exploration,Assessment and Long-term Follow-up(IDEAL)framework(stage 2 b).Paritcipants:The study will recruit 1,036 patients with cases of locally advanced AEG(Siewert typeⅡ/Ⅲ,clinical stage cT2-4 aN0-3 M0),and 518 will be assigned to either the laparoscopy group or the open group.Interventions:Patients will receive lower mediastinal lymphadenectomy along with either total or proximal gastrectomy.Primary and secondary outcome measures:The primary endpoint is the number of lower mediastinal lymph nodes retrieved,and the secondary endpoints are the surgical safety and prognosis,including intraoperative and postoperative lower-mediastinal-lymphadenectomy-related morbidity and mortality,rate of rehospitalization,R0 resection rate,3-year local recurrence rate,and 3-year overall survival.Conclusions:The study will provide data for the guidance and development of surgical treatment strategies for AEG.Trial registration number:The study has been registered in ClinicalTrials.gov(No.NCT04443478).

Anatomical variation of infra-pyloric artery origination： A prospective multicenter observational study (IPA-Origin)

Objective： Infra-pyloric artery （IPA） is an important anatomical landmark in treatment of gastric cancer and is the key vessel for pylorus-preserving gastrectomy and subgroup of infra-pyloric lymph nodes. However, its anatomical variation is not thoroughly understood. Our study aimed to clarify the origination of the IPA. Methods： We did this prospective, multicenter, open-label, observational study at gastric surgery departments of 34 hospitals in China. Gastric cancer patients aged 18 years or older and scheduled to undergo elective total or distal gastrectomy were assigned. During the surgery, IPA dissecting and exposing the origination point with photographs or video clips were required. The primary outcome was the origination of the IPA. Analysis of variance, χ2 tests and Fisher＇s tests were used to analyze the differences between groups. The study is registered at Clinicaltrials.gov （No. NCT03071237）. Results： Between May 8 and July 31, 2017, 429 patients were assigned for the study, and 419 （97.7%） patients had the IPA dissected and recorded through photograph or video and were included in the primary outcome analysis. The median age was 62 years old, and 73.7% were male. Among the patients, 78.5% received laparoscopic surgery. Single IPA origination was identified in 398 （95.0%） patients, including gastroduodenal artery （GDA） in 154 （36.8%） patients, anterior superior pancreaticoduodenal artery （ASPDA） in 130 （31.0%） patients, and right gastroepiploic artery （RGEA） in 114 （27.2%） patients. Fifteen （3.6%） patients were identified with multiple IPA and 6 （1.4%） patients were identified as IPA absence. The differences in the distribution of surgical approach （P=0.003） and geographic area （P=0.030） were statistically significant. No difference was shown in sex, age, gastrectomy type, tumor location, and clinical T, N and M stage. Conclusions： Our study found that the IPA originates from GDA, ASPDA and RGEA in similar proportions. Laparoscopic surgery may be more helpful in dissection of the IPA than open surgery.

Deciphering the contributions of spectral and structural data to wheat yield estimation from proximal sensing

Accurate, efficient, and timely yield estimation is critical for crop variety breeding and management optimization. However, the contributions of proximal sensing data characteristics(spectral, temporal, and spatial) to yield estimation have not been systematically evaluated. We collected long-term, hypertemporal, and large-volume light detection and ranging(Li DAR) and multispectral data to(i) identify the best machine learning method and prediction stage for wheat yield estimation,(ii) characterize the contribution of multisource data fusion and the dynamic importance of structural and spectral traits to yield estimation, and(iii) elucidate the contribution of time-series data fusion and 3 D spatial information to yield estimation. Wheat yield could be accurately(R^(2)= 0.891) and timely(approximately-two months before harvest) estimated from fused Li DAR and multispectral data. The artificial neural network model and the flowering stage were always the best method and prediction stage, respectively. Spectral traits(such as CIgreen) dominated yield estimation, especially in the early stage, whereas the contribution of structural traits(such as height) was more stable in the late stage. Fusing spectral and structural traits increased estimation accuracy at all growth stages. Better yield estimation was realized from traits derived from complete 3 D points than from canopy surface points and from integrated multi-stage(especially from jointing to heading and flowering stages) data than from single-stage data. We suggest that this study offers a novel perspective on deciphering the contributions of spectral, structural, and timeseries information to wheat yield estimation and can guide accurate, efficient, and timely estimation of wheat yield.

胃癌胃镜活检标本HER-2检测中国专家共识(2023版)

胃癌是最常见的消化道恶性肿瘤之一。人表皮生长因子受体-2(human epidermal growth factor receptor-2,HER-2)是胃癌(包括胃食管结合部腺癌)临床治疗的重要靶点。规范、准确的胃镜活检标本HER2表达状态检测对于胃癌分子分型与选择抗HER-2靶向药物治疗具有重要意义。本共识基于循证医学证据和国际通行的Delphi法,在胃镜活检标本HER-2检测的临床意义、适用人群、活检操作规范、标本前期处理、检测方法、检测质量控制与多学科合作等方面达成初步统一,以期对临床工作提供指导。

Reception of infrasound and audio current in derma nerves

Determining the frequency range of derma nerve that responds to audio current is fundamental for the development of skin-hearing technology. Previous studies have shown that the range of derma nerve responding to audio current is 15-15 000 Hz, because audio amplification is not separated from the step-up transformer. Therefore, the present study used a signal generator which directly drives plane electrodes, simplified the original experimental environment for skin-hearing, measured lower limit voltage of frequency for derma nerve receiving pulse current signals, and revealed that the frequency range of human derma nerve response was as wide as 0.1-30 000 Hz. Results demonstrate that human derma nerve receives audio signals and infrasound within a wide frequency range.