Knowledge-guided machine learning can improve carbon cycle quantification in agroecosystems.

Accurate and cost-effective quantification of the carbon cycle for agroecosystems at decision-relevant scales is critical to mitigating climate change and ensuring sustainable food production. However, conventional process-based or data-driven modeling approaches alone have large prediction uncertainties due to the complex biogeochemical processes to model and the lack of observations to constrain many key state and flux variables. Here we propose a Knowledge-Guided Machine Learning (KGML) framework that addresses the above challenges by integrating knowledge embedded in a process-based model, high-resolution remote sensing observations, and machine learning (ML) techniques. Using the U.S. Corn Belt as a testbed, we demonstrate that KGML can outperform conventional process-based and black-box ML models in quantifying carbon cycle dynamics. Our high-resolution approach quantitatively reveals 86% more spatial detail of soil organic carbon changes than conventional coarse-resolution approaches. Moreover, we outline a protocol for improving KGML via various paths, which can be generalized to develop hybrid models to better predict complex earth system dynamics.

Functional characterization of polyol/monosaccharide transporter 1 in Lotus japonicus.

Polyol/Monosaccharide Transporters (PLTs/PMTs) localized in the plasma membrane have previously been identified in plants. The physiological role and the functional properties of these proteins in legume plants are, however, unclear. Here we describe the functional analysis of LjPLT1, a plasma membrane-localized PLT protein from Lotus japonicus. The LjPLT1 gene was strongly expressed in the vascular tissue of roots, stems and leaves. Expression of the LjPLT1 cDNAs in yeast revealed that the protein functions as a broad-spectrum H+ -symporter for both linear polyols of sorbitol and mannitol, and cyclic polyol myo-inositol. It also catalyzes the transport of different hexoses, including fructose, glucose, galactose and mannose. Overexpression of LjPLT1 (OELjPLT1) results in inhibition of plant growth and a decrease in nodule nitrogenase activity in L. japonicus. The soluble sugars were increased in newly expanded leaves, roots and nodules but decreased in mature leaves in OELjPLT1 plants. In addition, the OELjPLT1 seedlings displayed an increased sensitivity to high content mannitol and boron toxicity, but neither drought nor salinity stresses. Taken together, the present study indicates that the LjPLT1 protein may participate in the translocation of hexoses/polyols to regulate multiple physiological and growth processes in L. japonicus.

Overexpression of LjPLT3 Enhances Salt Tolerance in Lotus japonicus.

Intracellular polyols are used as osmoprotectants by many plants under environmental stress. However, few studies have shown the role of polyol transporters in the tolerance of plants to abiotic stresses. Here, we describe the expression characteristics and potential functions of Lotus japonicus polyol transporter LjPLT3 under salt stress. Using LjPLT3 promoter-reporter gene plants showed that LjPLT3 was expressed in the vascular tissue of L. japonicus leaf, stem, root, and nodule. The expression was also induced by NaCl treatment. Overexpression of LjPLT3 in L. japonicus modified the growth rate and saline tolerance of the transgenic plants. The OELjPLT3 seedlings displayed reduced plant height under both nitrogen-sufficient and symbiotic nitrogen fixation conditions when 4 weeks old. The nodule number of OELjPLT3 plants was reduced by 6.7-27.4% when 4 weeks old. After exposure to a NaCl treatment in Petri dishes for 10 days, OELjPLT3 seedlings had a higher chlorophyll concentration, fresh weight, and survival rate than those in the wild type. For symbiotic nitrogen fixation conditions, the decrease in nitrogenase activity of OELjPLT3 plants was slower than that of the wild type after salt treatment. Compared to the wild type, both the accumulation of small organic molecules and the activity of antioxidant enzymes were higher under salt stress. Considering the concentration of lower reactive oxygen species (ROS) in transgenic lines, we speculate that overexpression of LjPLT3 in L. japonicus might improve the ROS scavenging system to alleviate the oxidative damage caused by salt stress, thereby increasing plant salinity tolerance. Our results will direct the breeding of forage legumes in saline land and also provide an opportunity for the improvement of poor and saline soils.

Genome-Wide Identification, Expression Patterns and Sugar Transport of the Physic Nut SWEET Gene Family and a Functional Analysis of JcSWEET16 in Arabidopsis.

The Sugars Will Eventually be Exported Transporters (SWEET) family is a class of sugar transporters that play key roles in phloem loading, seed filling, pollen development and the stress response in plants. Here, a total of 18 JcSWEET genes were identified in physic nut (Jatropha curcas L.) and classified into four clades by phylogenetic analysis. These JcSWEET genes share similar gene structures, and alternative splicing of messenger RNAs was observed for five of the JcSWEET genes. Three (JcSWEET1/4/5) of the JcSWEETs were found to possess transport activity for hexose molecules in yeast. Real-time quantitative PCR analysis of JcSWEETs in different tissues under normal growth conditions and abiotic stresses revealed that most are tissue-specifically expressed, and 12 JcSWEETs responded to either drought or salinity. The JcSWEET16 gene responded to drought and salinity stress in leaves, and the protein it encodes is localized in both the plasma membrane and the vacuolar membrane. The overexpression of JcSWEET16 in Arabidopsis thaliana modified the flowering time and saline tolerance levels but not the drought tolerance of the transgenic plants. Together, these results provide insights into the characteristics of SWEET genes in physic nut and could serve as a basis for cloning and further functional analysis of these genes.

A d-pinitol transporter, LjPLT11, regulates plant growth and nodule development in Lotus japonicus.

Polyol transporters have been functionally characterized in yeast and Xenopus laevis oocytes as H+-symporters with broad substrate specificity, but little is known about their physiological roles in planta. To extend this knowledge, we investigated the role of LjPLT11 in Lotus japonicus-Mesorhizobium symbiosis. Functional analyses of LjPLT11 in yeast characterized it as an energy-independent transporter of xylitol, two O-methyl inositols, xylose, and galactose. We showed that LjPLT11 is located on peribacteroid membranes and functions as a facilitative transporter of d-pinitol within infected cells of L. japonicus nodules. Knock-down of LjPLT11 (LjPLT11i) in L. japonicus accelerated plant growth under nitrogen sufficiency, but resulted in abnormal bacteroids with corresponding reductions in nitrogenase activity in nodules and plant growth in the nitrogen-fixing symbiosis. LjPLT11i nodules had higher osmotic pressure in cytosol, and lower osmotic pressure in bacteroids, than wild-type nodules both 3 and 4 weeks after inoculation of Mesorhizobium loti. Levels and distributions of reactive oxygen species were also perturbed in infected cells of 4-week-old nodules in LjPLT11i plants. The results indicate that LjPLT11 plays a key role in adjustment of the levels of its substrate pinitol, and thus maintenance of osmotic balance in infected cells and peribacteroid membrane stability during nodule development.

LAZY3 plays a pivotal role in positive root gravitropism in Lotus japonicus.

LAZY1 family genes play important roles in both shoot and root gravitropism in plants. Here we report a Lotus japonicus mutant that displays negative gravitropic response in primary and lateral roots. Map-based cloning identified the mutant gene LAZY3 as a functional ortholog of the LAZY1 gene. Mutation of the LAZY3 gene reduced rootward polar auxin transport (PAT) in the primary root, which was also insensitive to the PAT inhibitor N-1-naphthylphthalamic acid. Moreover, immunolocalization of enhanced green fluorescent protein-tagged LAZY3 in L. japonicus exhibited polar localization of LAZY3 on the plasma membrane in root stele cells. We therefore suggest that the polar localization of LAZY3 in stele cells might be required for PAT in L. japonicus root. LAZY3 transcripts displayed asymmetric distribution at the root tip within hours of gravistimulation, while overexpression of LAZY3 under a constitutive promoter in lazy3 plants rescued the gravitropic response in roots. These data indicate that root gravitropism depends on the presence of LAZY3 but not on its asymmetric expression in root tips. Expression of other LAZY genes in a lazy3 background did not rescue the growth direction of roots, suggesting that the LAZY3 gene plays a distinct role in root gravitropism in L. japonicus.

[Three-dimensional total endoscopic thyroidectomy for thyroid carcinoma: a series of 32 cases].

OBJECTIVE: To summarize the experiences of applying three-dimensional (3D) technique in scarless endoscopic thyroidectomy (SET) via anterior chest approach. METHODS: Medical records of patients who undenvent SET using 3D technique from December 2013 to May 2014 were retrospectively reviewed. A total of 32 patients who had a preoperative ultrasound-guided fine-needle aspiration cytology diagnosis of unilateral papillary thyroid carcinoma and underwent lobectomy associated with central lymph node dissection were included in this study. All patients were female with a mean age of (37 ± 10) years at diagnosis. In addition, 45 female patients who underwent traditional endoscopic thyroidectomy at the same period were randomly selected as control. RESULTS: All surgical procedures were successfully finished. The mean surgical time in 3D group was (91. 7 ± 11. 4) minutes, and mean hospitalization time was (3. 2 ± 0. 5) days. Contemporary hoarseness was observed in one patient, and no bleeding, infection, hypocalcemia and other postsurgical complications were observed. Compared to the traditional endoscopic surgery group, 3 D group had significantly shorter surgical time of lobectomy ((23. 2 ± 5. 1) minutes vs. (28. 0 ± 5. 0) minutes, t = 4. 156, P = 0. 000). Negative results were seen in the time taking of creating surgical space ((14. 6 ± 3. 3) minutes vs. (15. 6 ± 2. 5) minutes), central lymph node dissection ((25. 1 ± 5. 4) minutes vs. (24. 4 ± 6. 3) minutes) and total surgical time ((91.7 ± 11. 4) minutes vs. (96. 1 ± 13. 0) minutes). CONCLUSION: Application of 3D technique in endoscopic surgery can offer 3D vision of the surgical field, thus significantly shorten lobectomy time and more easily to achieve fine dissection and functional protection of recurrent laryngeal nerves, parathyroids and other vital anatomic structures.

Genetic variation in the major mitotic checkpoint genes and risk of breast cancer: a multigenic study on cancer susceptibility.

The mitotic checkpoint system is a mechanism essential for maintaining genomic stability and defects which have been linked to cancer development. We conducted this hospital-based case-control study to investigate whether genetic variants in three major spindle checkpoint genes (BUB3, MAD2L1, and BUB1) had any bearing on an individual risk of breast cancer (BC). A total of 462 incident BC patients and 529 cancer-free controls were enrolled in this study. Results showed that neither variants in BUB3 nor variants in MAD2L1 caused any significant effect on the risk of BC. However, the variant rs12623473 in BUB1 was significantly associated with increased BC risk with the odds ratio (OR) of 1.30 (95 % confidence interval (CI) 1.03-1.64) under the allelic model. The estimated population attributable risk of one copy of the risk allele for developing BC was 10.3 %. The bioinformatics analysis suggested that this variant may regulate the transcriptional ability of BUB1.

Endoscopic lateral neck dissection via breast approach for papillary thyroid carcinoma: a preliminary report.

BACKGROUND: Traditional open surgery for lateral neck dissection for patients with papillary thyroid carcinoma (PTC) requires a large incision to obtain adequate exposure of the surgical field, leaving an unsightly scar. We applied scarless (in the neck) endoscopic thyroidectomy (SET) via breast approach to lateral neck dissection for PTC and evaluated its feasibility and safety. METHODS: Between July 2007 and October 2009, 11 T1 (tumor size not exceeding 2 cm) low-risk PTC female patients with suspected lymph node metastasis at level III or IV were selected for this procedure. After accomplishing thyroidectomy and central compartment dissection, ipsilateral level III and IV dissection via breast approach was performed. The steps of endoscopic lateral neck dissection were similar to that of conventional surgery except that the lateral cervical compartment was exposed by splitting the sternocleidomastoid muscles (SCM) longitudinally. RESULTS: This procedure was carried out successfully in all 11 patients. Mean operative time for lateral neck dissection was 94.3 min (range 77-123 min). No significant blood loss or complications occurred. Average postoperative hospital stay was 4.3 days (range 3-6 days). Ten patients had lymph node metastasis in both central and lateral zones, while one patient had central zone metastasis only. Mean lymph node yield in the lateral compartment was 18.3 (range 9-26). No evidence of residual or recurrent disease was found at follow-up. The cosmetic results of this procedure were excellent. CONCLUSIONS: Endoscopic lateral neck dissection via breast approach is feasible and safe with excellent cosmetic results for selected cases of PTC. Further study based on large comparative series and long-term follow-up is needed to verify its oncological validity.

[Diagnosis and treatment of parathyroid carcinoma: 9 cases report and literature review].

OBJECTIVE: To investigate the diagnosis and surgical treatment of parathyroid carcinoma. METHODS: The clinical data of 9 cases of parathyroid carcinoma treated from January 1967 to December 2009 was analyzed retrospectively with the review of related Chinese literatures. RESULTS: Parathyroid carcinoma accounted for 8.9% (8/90) of all patients with primary hyperparathyroidism in our hospital, and the other one case was transferred from another hospital. Of the patients, 8 cases were found with primary hyperparathyroidism. Primary surgery was carried out with small incision: 5 patients underwent en bloc resection, among which, 3 cases received central lymph node dissection; 2 patients received simple parathyroidectomy; one case underwent palliative tumor resection. The case from another hospital received subtotal thyroidectomy. Considering preoperative, intraoperative data and frozen sections pathology, all patients were diagnosed as parathyroid carcinoma. Nine patients were followed-up for 1 - 14 years, no recurrence occurred, and the patient received palliative resection died from carcinoma two years after the operation. In previous Chinese literatures and this group, there were total 146 patients reported as parathyroid carcinoma. Those patients were diagnosed through routine histopathology, accounted for 1.8% - 11.5% of patients with primary hyperparathyroidism. CONCLUSIONS: The diagnosis of parathyroid carcinoma is established according to severe hypercalcemia, clinical features, subset B-ultrasound and Tc(99m)-sestamibi scanning, intraoperative finding of adherence to close structures and histopathology. The initial surgical procedure of choice is en bloc resection of the tumor by minimally invasive small incision, including adjacent structures and ipsilateral thyroidectomy. The prognosis is favorable after the operation.

[Endoscopic thyroidectomy through anterior chest and breast approach for papillary thyroid microcarcinoma].

OBJECTIVE: To evaluate the operative feasibility and safety of endoscopic thyroidectomy through anterior chest and breast approach for the treatment of the patients with papillary thyroid microcarcinoma (PTMC). METHODS: Endoscopic thyroidectomy was attempted in 164 patients with thyroid diseases. For 28 cases, which were diagnosed as PTMC by frozen section intraoperatively, lobotomy plus central compartment dissection and contralateral subtotal lobotomy was achieved completely by endoscopic thyroidectomy. There were 27 females and 1 male, and their average age was 35.2 years old. Twelve and sixteen cases were diagnosed preoperatively as thyroid microcarcinomas and benign tumors, respectively. RESULTS: The operation time of the 28 cases was (115 +/- 43) min. The maximum diameter of PTMC was 0.2 to 1.0 cm with a mean of 0.56 cm. 17.9% (5/28) of the PTMC patients had transient vocal cord palsy and restored after 1 to 2 months postoperatively. There were no complications such as subcutaneous emphysema and postoperative bleeding and postoperative hypocalcaemia. 46.4% (13/28) had node involvement of the central compartment. Postoperative ultrasonography and scintigraphy showed no evidence of recurrence or residual thyroid tissue in the thyroid bed where lobotomy was performed. CONCLUSIONS: The endoscopic thyroidectomy through anterior chest and breast approach is a choice of the surgical treatment for selected cases of PTMC.

Preoperative localization and minimally invasive management of primary hyperparathyroidism concomitant with thyroid disease.

The coexistence of thyroid diseases with primary hyperparathyroidism (PHPT) can present a challenge in the clinical diagnosis and management for these patients. This study aims to determine the frequency of coexisting thyroid gland lesions in a consecutive series patients with PHPT, and to analyze the clinical features, diagnosis and treatment of these patients. Twenty-two cases of a total of 52 PHPT patients who had synchronous thyroid and parathyroid pathology were surgically managed in this study. Thirteen patients had ipsilateral thyroid nodules, and 9 patients had thyroid nodules in contralateral or bilateral side. Seven patients underwent direct parathyroidectomy and hemithyroidectomy via a mini-incision (about 3 cm), while other 15 procedures were converted to Kocher incision. Seventeen nodular goiter (32.7%), 2 thyroiditis (3.8%), 2 thyroid adenoma (3.8%) and 1 thyroid carcinoma (1.9%) coexisting with parathyroid adenoma were pathologically diagnosed. The sensitivity of preoperative ultrasonography (US) and methoxy-isobutyl-isonitrile (MIBI) scintigraphy for parathyroid lesions was 63.6% and 85.7%; and the overall positive predictive values for MIBI and US were 100% and 95.5% respectively. A high incidence of thyroid diseases that coexisted with PHPT in literatures was briefly reviewed. Our study illustrated the need for clinical awareness of concomitant PHPT and thyroid disease. A combination of US, computed tomography (CT) and MIBI scintigraphy would be recommended for preoperative localization of enlarged parathyroid adenoma and for evaluation of thyroid lesions. Synchronous treatment of associated thyroid abnormalities is desirable, and open minimally invasive surgical approach with additional resection of isolated ipsilateral thyroid nodules is possible in some of these patients.

Diagnosis and management of colonic injuries following blunt trauma.

AIM: To retrospectively evaluate the preoperative diagnostic approaches and management of colonic injuries following blunt abdominal trauma. METHODS: A total of 82 patients with colonic injuries caused by blunt trauma between January 1992 and December 2005 were enrolled. Data were collected on clinical presentation, investigations, diagnostic methods, associated injuries, and operative management. Colonic injury-related mortality and abdominal complications were analyzed. RESULTS: Colonic injuries were caused mainly by motor vehicle accidents. Of the 82 patients, 58 (70.3%) had other associated injuries. Laparotomy was performed within 6 h after injury in 69 cases (84.1%), laparoscopy in 3 because of haemodynamic instability. The most commonly injured site was located in the transverse colon. The mean colon injury scale score was 2.8. The degree of faecal contamination was classified as mild in 18 (22.0%), moderate in 42 (51.2%), severe in 14 (17.1%), and unknown in 8 (9.8%) cases. Sixty-seven patients (81.7%) were treated with primary repair or resection and anastomosis. Faecal stream diversion was performed in 15 cases (18.3%). The overall mortality rate was 6.1%. The incidence of colonic injury-related abdominal complications was 20.7%. The only independent predictor of complications was the degree of peritoneal faecal contamination (P = 0.02). CONCLUSION: Colonic injuries following blunt trauma are especially important because of the severity and complexity of associated injuries. A thorough physical examination and a combination of tests can be used to evaluate the indications for laparotomy. One stage management at the time of initial exploration is most often used for colonic injuries.

[Cloning of human vascular endothelial growth factor cDNA and its expression in COS-7 cells]

OBJECTIVE: To clone vascular endothelial growth factor (VEGF) cDNA gene, construct its eukaryotic expression vector and to express this recombinant plasmid in COS-7 cells. METHODS: Human VEGF165 cDNA was amplified by RT PCR from human ovarian carcinoma. After DNA sequenced, the VEGF165 cDNA was inserted into eukaryotic expression vector pcDNA3.1(-). The recombinant plasmid pcDNA3.1 VEGF165 containing VEGF165 cDNA was identified by enzyme digestion and transferred into COS-7 cells mediated by liposome. The transient expression of VEGF was detected by immunohistochemical staining. RESULTS: The cloned VEGF165 cDNA was confirmed by enzyme digestion and DNA sequence analysis. The immunohistochemical results showed that the VEGF165 protein was expression in COS-7 cells 72 h after gene transfer. CONCLUSION: VEGF165 cDNA gene successfully cloned and expressed in COS-7 cells.