Objective:To study the precision of 3D printing coplanar template (3D-PCT) assisted CT-guided radioactive particle implantation using two types of phantoms, and compare the differences between the phantoms, in order to provide reference for radioactive particle implantation.Methods:The needle inserting path was designed in the brachytherapy treatment planning system (BTPS) and the needle tip coordinates were obtained. Following the needle inserting path, the implant needles were inserted into the custom and the liver phantoms, respectively. Then gold markers were implanted through the needles. Subsequently, the needles were withdrawn by 10 mm, and the cold sources were implanted. The coordinates of needle tips, gold markers, and cold sources were recorded. The precision of implanted needles, first particles, and particles after needle withdrawal were obtained by calculating the distance between two points in the space. Finally, the differences between the two phantoms were compared through independent samples t-test. Results:In the 3D-PCT-assisted CT-guided radioactive particle implantation, the precision of implanted needles, first particles, and particles after needle withdrawal in the custom and the liver phantoms was (1.89±0.72) and (2.14±0.88 ) mm ( P>0.05), (2.03±1.14) and (2.42±1.12) mm ( P>0.05), and (-1.96±1.29) and (-2.82±0.91) mm ( t=2.09, P=0.046), respectively. Conclusions:The 3D-PCT-assisted CT-guided radioactive particle implantation is efficient, stable, and precise, showing slight precision differences between the two phantoms.

Objective: To establish a dynamic syndromic surveillance system in the border areas of Yunnan Province based on information technology, evaluate its effectiveness and timeliness in the response to common communicable disease epidemics and improve the communicable disease prevention and control in border areas. Methods: Three border counties were selected for full coverage as study areas, and dynamic surveillance for 14 symptoms and 6 syndromes were conducted in medical institutions, the daily collection of information about students' school absence in primary schools and febrile illness in inbound people at border ports were conducted in these counties from January 2016 to February 2018 to establish an early warning system based on mobile phone and computer platform for a field experimental study. Results: With syndromes of rash, influenza-like illness and the numbers of primary school absence, the most common communicable disease events, such as hand foot and mouth disease, influenza and chickenpox, can be identified 1-5 days in advance by using EARS-3C and Kulldorff time-space scanning models with high sensitivity and specificity. The system is easy to use with strong security and feasibility. All the information and the warning alerts are released in the form of interactive charts and visual maps, which can facilitate the timely response. Conclusions: This system is highly effective and easy to operate in the detection of possible outbreaks of common communicable diseases in border areas in real time, so the timely and effective intervention can be conducted to reduce the risk of local and cross-border communicable disease outbreaks. It has practical application value.
Humans ; Influenza, Human ; Sentinel Surveillance ; Syndrome ; China ; Cell Phone

Seed quality plays an important role in the agricultural and animal husbandry production, the effective utilization of genetic resources, the conservation of biodiversity and the restoration and reconstruction of plant communities. Seed aging is a common physiological phenomenon during storage. It is a natural irreversible process that occurs and develops along with the extension of seed storage time. It is not only related to the growth, yield and quality of seed and seedling establishment, but also has an important effect on the conservation, utilization and development of plant germplasm resources. The physiological mechanisms of seed aging are complex and diverse. Most studies focus on conventional physiological characterization, while systematic and comprehensive in-depth studies are lacking. Here we review the recent advances in understanding the physiology of seed aging process, including the methods of seed aging, the effect of aging on seed germination, and the physiological and molecular mechanisms of seed aging. The change of multiple physiological parameters, including seed vigor, electrical conductivity, malondialdehyde content and storage material in the seed, antioxidant enzyme activity and mitochondrial structure, were summarized. Moreover, insights into the mechanism of seed aging from the aspects of transcriptome, proteome and aging related gene function were summarized. This study may facilitate the research of seed biology and the conservation and utilization of germplasm resources.
Germination ; Plants ; Proteome ; Seedlings ; Seeds/genetics*

Objective:To verify the accuracy and feasibility of radioactive 125I seed implantation assisted by an optical navigation system and a 3D-printing non-coplanar template in the treatment of recurrent head and neck cancers. Methods:A total of 12 patients with recurrent head and neck cancer treated with radioactive 125I seed implantation assisted by an optical navigation system and 3D-printing non-coplanar template were enrolled from Dec 2018 to Dec 2019.The pre-plan and post-implant implantation needle number and implanted seed number were recorded.Meanwhile, their dosimetric parameters were compared, including D90, minimum peripheral dose (MPD), V100, V150, V200, conformity index (CI), external index (EI), and the homogeneity index (HI) of the target volume. Results:The median lesion volume was 31.5 cm 3, the median number of seeds was 61.5, and the median prescription dose was 130 Gy.The means of the pre-plan D90, MPD, V100, V150 and V200 were 134.2, 64.6, 93.3, 75.3 and 39.3 Gy, respectively, while those of post-implant D90, MPD, V100, V150, and V200 were 146.7, 68.94, 97.47, 80.40 and 48.30 Gy, respectively, with no statistically significant difference ( P>0.05). Meanwhile, there was no statistically significant difference between the pre-plan and post-implantation needle number, implanted seed number, CI, HI, and EI ( P>0.05). In terms of postoperative dose quality assessment, eight cases were rated excellent (66.6%) and four cases were rated good (33.3%). Conclusions:Radioactive 125I seed implantation assisted by an optical navigation system and 3D-printing non-coplanar template can be accurately performed in the treatment of recurrent head and neck cancer, with good consistency between pre-plan and post-implant dosimetric parameters and thus of prospective potential in clinical application.

Objective:To compare preoperative planning parameters between non-coplanar and coplanar template-assisted radioactive seed implantation in the treatment of pancreatic cancers, in order to guide clinical application.Methods:Patients with pancreatic cancers who received external irradiation in the Peking University Third Hospital from Jan 2017 to May 2019 were selected.Their image information was imported into the brachytherapy planning system, and the non-coplanar plan and coplanar plan were designed individually.Each patient′s prescription dose was set to 110 Gy, and the activity of the radioactive seeds were 0.4 mCi(1 Ci=3.7×10 10Bq), respectively.For the two plans, the dose distribution was optimized and dosimetric parameters were compared, including the implantation needle number, the implanted seed number, the minimum prescription doses delivered to 90% and 100% of the target volume ( D90 and D100), mean percentages of volume receiving 100%, 150% and 200% of the prescription doses ( V100, V150 and V200), conformity index (CI), external index (EI), and homogeneity index (HI) of the target volume, as well as the doses of 2 cm 3 and 5 cm 3 ( D2 cm 3 and D5 cm 3) of the surrounding normal organs such as the small intestines, colon, duodenum, stomach, and spinal cord. Results:The implantation needle number in the coplanar plan was slightly higher than that in the non-coplanar plan, namely 18.63 vs. 16.45 ( t=-3.239, P <0.05). The implanted seed number was equivalent, namely 90.2 vs. 91.01, with no statistical difference ( P>0.05). There was no significant difference between D90, D100, V100, V150, V200, CI, EI, and HI in the target area of the two plans ( P>0.05). Meanwhile, there was no obvious difference in D2 cm 3 and D5 cm 3 of normal organs including the small intestines, colon, duodenum, stomach, and spinal cord ( P>0.05). Conclusions:With both the coplanar plan and the non-coplanar plan, the prescription doses can be achieved and meanwhile, there are very small differences in the doses of normal organs.Given that 3D-printing non-coplanar and coplanar templates have their own characteristics, it is necessary to choose them according to specific situations.

Objective: To compare the preoperative and postoperative dosimetric parameters in the treatment of spinal metastasis, and to verify the accuracy of 3D-printing non-coplanar template (3D-PNCT) combined with CT-guided ¹²⁵I seed implantation for the treatment of spinal metastasis. Methods: The treatment plans of 7 patients with spinal metastasis (9 lesions) from 2016 to 2018 receiving 3D-PNCT in combination with CT-guided ¹²⁵I seed implantation were retrospectively analyzed. The dosimetric parameters including homogeneity index (HI), conformal index (CI), external index (EI), dose of 90% target volume(D₉₀), mPD, volume percent of 100%, 150%, and 200% prescribed dose V₁₀₀、V₁₅₀、V₂₀₀ and D_2cm³ of spinal cord were compared before and after operation. The british columbia cancer ageny particle implantation quality evaluation standard was applied to evaluate the quality of implantation. Results: The HI, EI and CI, D₉₀, mPD, V₁₀₀, V₁₅₀, V₂₀₀ and D_2cm³ of spinal cord did not significantly differ before and after the plan (all P>0.05). Five were evaluated as excellent and 4 were assessed as good. Conclusion The postoperative dosimetric parameters of 3D-PNCT combined with CT guided ¹²⁵I seed implantation of spinal metastasis are basically consistent with preoperative dosimetric parameters. The postoperative plans are evaluated as excellent or good, suggesting that the technology has a good therapeutic accuracy in the treatment of spinal metastasis.

Objective:To compare the difference of preoperative and postoperative plans of navigation-assisted three-dimensional (3D)-printing template combined with CT-guided radioactive 125I seeds implantation for malignant tumors, and verify preliminarily the plan quality of optical navigation-assisted seeds implantation. Methods:From December 2018 to November 2019, a total of 20 patients (10 males, 10 females, median age: 60.5 years) with malignant tumors received navigation-assisted 3D-printing template combined with CT-guided radioactive 125I seeds implantation in Peking University Third Hospital. Eight cases were implanted in the head and neck, 1 case in the chest wall, 9 cases in the pelvis and 2 cases in the paravertebral and/or retroperitoneal region. The median prescription dose was 150 Gy. The data in the preoperative and postoperative plans was compared, including seeds number, needles number, and some dosimetry parameters. Dosimetry parameters including dose delivered to 90% gross tumor volume (GTV) ( D90), percentage of GTV received 100%, 150%, and 200% of the prescribed dose ( V100, V150, V200), minimum peripheral dose (MPD), conformal index (CI), external index (EI), homogeneity index (HI) of target volume, and 2 cm 3 range of spinal cord receiving dose ( D2 cm 3). Paired t test and Wilcoxon signed rank test were used to analyze the data. Results:The needles number of preoperative and postoperative plans was the same (both 12 (9, 19)), and the seeds number of postoperative plan was more than preoperative plan with no significant difference (51(35, 68) vs 49(35, 63); z=1.859, P>0.05). The MPD of postoperative plans was higher than preoperative plans ((80.52±14.89) vs (67.22±20.56) Gy, t=-3.769, P=0.001). There were no significant differences in other dosimetry parameters between the two plans ( t values: -0.533, -0.423, z values: from -0.849 to 1.416, all P>0.05). Postoperative dose quality assessment was excellent in 17 cases (17/20), good in 2 cases (2/20) and middle in 1 case (1/20). Conclusions:The quality of the implantation is good under the guidance of combined mode. The actual target dose after operation can meet the requirements of preoperative planning.

Objective: To understand the epidemiologic features of the rabies in Xishuang banna prefecture of Yunnan province, China in 2008-2017 and the viral molecular-evolution characteristics. Methods: The data of rabies case questionnaire were collected. The brain tissue samples from mad dogs, suspicious sick dogs and human brain tissue, saliva and cerebrospinal fluid samples from rabies patients were collected in Xishuangbanna. Coding region of nucleoprotein and glycoprotein genes were amplified by RT-PCR and sequenced. Homology and phylogenetic analysis were performed using the relevant bioinformatics software. Results: A total of 62 cases of human rabies were occurred in 28 districts of the 3 counties, Xishuangbanna prefecture in 2008-2017. Of them, 37 cases in Jinghong county, 15 in Menghai county and 10 in Mengla county. In which 48 cases were bitten by domestic dogs (77.42%), 11 cases were bitten by wild dogs (17.74%). Rabies case was occurred every year in the past decade. The seasonal incidence was not obvious. The majority of patients were aged from 30 to 59 years-old, with the youngest 1 year-old and the eldest 91 year-old. The male to female ratio was 1.70∶1, most cases were farmers. The nucleotide sequences of nucleoprotein gene of 9 virus strains (7 from Jinghong, 1 from Menghai and 1 from Mengla) were obtained from the samples of dogs and patients. Homology and phylogenetic analyses indicated that the 5 strains belonged to clade China-Ⅰ, 3 clade China-Ⅱ and 1 clade China-Ⅵ. The nucleotide sequences of glycoprotein gene of 5 virus strains (3 from Jinghong, 1 from Menghai and 1 from Mengla) were obtained from these positive samples, and all were clade China-Ⅰ, it is same with nucleoprotein genes analysis result from these 5 virus strains. These China-Ⅰ and China-Ⅱ strains from Xishuangbanna have a closer genetic relationship with same clade strains isolated from Pu’er and other prefectures of Yunnan province as well as Sichuan, Guizhou and Guangxi. The China-Ⅵ strain from Xishuangbanna share high homology and genetic relationship with China-Ⅵ strains isolated from southwestern Yunnan and neighbouring countries such as Myanmar, Laos and Vietnam in recent years. Conclusions In Xishuangbanna, rabies mainly occurred in rural area and domestic dog was the main source of transmission. These RABV clades China-Ⅰ, China-Ⅱ and China-Ⅵ were found in this region and the China-Ⅰ was principal clade. The transmission source of China-Ⅰ and China-Ⅱ were from adjacent areas in the province and China-Ⅵ was from Myanmar and Laos.

Objective To analyze the qualified rate of the fiducial markers during 3D-printing co-planar template assisted CT-guided implantation in stereotactic body radiation therapy by CyberKnife,and to explore the cause of the unavailable markers in order to provide the reference for the fiducial implantation,treatment planning and radiotherapy delivery.Methods From March to December 2017,a total of 52 cases were planned to stereotactic body radiation therapy(SBRT) using CyberKnife by fiducial tracking,and the fiducial markers were implanted based on CT-guided 3D-printing co-planar template,including 22 in lung,12 in liver,5 in mediastinal lymph node,8 in retroperitoneal lymph node,3 in pancreas,each in celiac and pelvic lymph nodes,respectively.Except 7 cases not fit for CyberKnife treatment,45 cases finished the treatment of CyberKnife,but there were 3 cases changed to spine tracking due to unqualified fiducial markers.The number of fiducial markers used and the qualified rate of fiducial markers were analyzed,and the cause of unqualified fiducial markers was studied.Results A total of 131 fiducial markers were impanted into 42 cases who finally received the treatment of CyberKnife by fiducial tracking,including 85 fiducial markers qualified (64.89％) and 46 fiducial markers unqualified (35.11％).The main causes of the unqualified fiducial markers varied,including outrange of rigidity error(26.08％),fiducial markers unavailable(41.31％),and other (32.61％).Conclusions The 3D-printing co-planar template assisted CT-guided implantation could reduce the number of puncture needles used,help to decrease the risk of puncture and trauma and the incidence of complications after the fiducial markers implantation.However,the fiducial markers implanted by this way would be abandoned by a variety of causes and should be taken into account before the fiducial markers implantation.

Objective To compare the dose distribution of postoperative plans with preoperative plans of 3D-printing template (coplanar and non-coplanar) assisted and CT-guided 125I seed implantation for the treatment of soft tissue sarcoma,and to explore the accuracy of treatment at dosimetry level.Methods From December 2015 to July 2017,19 patients with soft tissue sarcoma (a total of 25 lesions)were treated with 3D printing template assisted and CT-guided 125I seed implantation in Peking University Third Hospital.All patients underwent preoperative assessment,CT simulation orientation,preoperative planning,3D-template printing,3D-template reduction,needle and seed implantation,postoperative dosimetry assessment,postoperative care and follow-up.The preoperative and postoperative dosimetric parameters were conpared.Ten cases of soft tissue sarcoma in superficial trunk or limbs were screened.Preoperative planning of coplanar template and non-coplanar template were designed respectively.The dosimetric parameters of preoperative planning guided of two templates were compared.Results Twentyfive 3D-printing templates were designed and constructed,and 25 lesions were totalled.There was no statistical difference between preoperative and postoperative dosimetric parameters.There was no statistical difference of the preoperative plan's dosimetric parameters between coplanar and non-coplanar in soft tissue sarcoma of superficial trunk/limbs.Conclusions The validation of actual dose distribution in postoperative plans assisted by 3D-printing template in 125I seed implantation showed that most of parameters could meet the expectation of preoperative plans,which indicated the improvement in accuracy for this new modality.For soft tissue sarcoma located in the superficial trunk/limbs,it was recommended to select the 3D-printing coplanar template firstly.