Gene transfer and nucleotide sequence evolution by Gossypium cytoplasmic genomes indicates novel evolutionary characteristics.

KEY MESSAGE: The DNA fragments transferred among cotton cytoplasmic genomes are highly differentiated. The wild D group cotton species have undergone much greater evolution compared with cultivated AD group. Cotton (Gossypium spp.) is one of the most economically important fiber crops worldwide. Gene transfer, nucleotide evolution, and the codon usage preferences in cytoplasmic genomes are important evolutionary characteristics of high plants. In this study, we analyzed the nucleotide sequence evolution, codon usage, and transfer of cytoplasmic DNA fragments in Gossypium chloroplast (cp) and mitochondrial (mt) genomes, including the A genome group, wild D group, and cultivated AD group of cotton species. Our analyses indicated that the differences in the length of transferred cytoplasmic DNA fragments were not significant in mitochondrial and chloroplast sequences. Analysis of the transfer of tRNAs found that trnQ and nine other tRNA genes were commonly transferred between two different cytoplasmic genomes. The Codon Adaptation Index values showed that Gossypium cp genomes prefer A/T-ending codons. Codon preference selection was higher in the D group than the other two groups. Nucleotide sequence evolution analysis showed that intergenic spacer sequences were more variable than coding regions and nonsynonymous mutations were clearly more common in cp genomes than mt genomes. Evolutionary analysis showed that the substitution rate was much higher in cp genomes than mt genomes. Interestingly, the D group cotton species have undergone much faster evolution compared with cultivated AD groups, possibly due to the selection and domestication of diverse cotton species. Our results demonstrate that gene transfer and differential nucleotide sequence evolution have occurred frequently in cotton cytoplasmic genomes.

Risk factor analysis for predicting cervical lymph node metastasis in papillary thyroid carcinoma: a study of 966 patients.

BACKGROUNDS: The aim of this study is to investigate the risk factors for the cervical lymph node metastasis in papillary thyroid carcinoma (PTC). METHODS: The clinicopathological data from the 966 PTC patients who underwent thyroid operation between January 2013 and December 2015 in the general surgery department of Shengjing Hospital of China Medical University were collected. The risk factors of predicting cervical lymph node metastasis were analyzed. RESULTS: Male, age ≤ 45 years old, tumor size> 1.0 cm, extrathyroidal extension (ETE), US features as microcalcification, were independent risk factors for central lymph node metastasis (CLNM) (P < 0.05). Only CLNM was independent risk factors for lateral lymph node metastasis (LLNM) (P < 0.05). The ROC curve showed that the cutoff value of the number of CLNM for predicting lateral lymph node metastasis was defined as 2.5 (Sensitivity = 0.535, Specificity = 0.722, AUC = 0.669, P < 0.05). When the number of CLNM > 3, OR value was significantly higher, suggesting that the risk of LLNM increased significantly. The incidence of LLNM in level III (66.8%) and level IV (67.3%) were significantly higher than level II (42.2%) and level V (21.3%) (P < 0.05). The incidence of LLNM and skip metastasis in tumor located in the upper 1/3 of the lobe was the highest (P < 0.05). CONCLUSIONS: Prophylactic central lymph node dissection should be performed in patients with risk factors as male, age ≤ 45 years old, tumor size> 1.0 cm, ETE and US features as microcalcification. Lateral lymph node dissection (LLND) should be more actively performed in patients with the number of CLNM> 3. Extent of LLND should include levels II, III, IV and V. Tumor located in the upper 1/3 of the lobe was vulnerable for LLNM and skip metastasis, so lymph node in lateral compartment should be noticed when lymph node status was preoperatively evaluated by imaging examination.

Expression of activator protein-1 in papillary thyroid carcinoma and its clinical significance.

BACKGROUND: The abnormal expression of activator protein-1(AP-1) has recently been investigated in a variety of tumors. While the relationship between AP-1 and thyroid cancer is poorly studied, our study was to evaluate the protein expression and clinical value of AP-1 in papillary thyroid carcinoma (PTC). METHODS: The expression of AP-1 was examined by immunohistochemistry on paraffin-embedded tissues obtained from PTC and correspondent paracancerous tissues of 82 patients. RESULTS: Compared with paracancerous tissues, AP-1 expression was significantly elevated in PTC tissues and the positive rate was 79.3% (65/82). Our study found a linear trend relationship between the expression of AP-1 and tumor size. However, the differences in AP-1 expression among gender, age, lymph node metastasis, number of lesions, location of the lesion, and extrathyroid invasion are not statistically significant. CONCLUSIONS: The expression of AP-1 plays an important role in the proliferation process of PTC.

Blind versus endoscopy-guided postpyloric feeding tube placement in adults with ischemic stroke: A retrospective cohort study.

BACKGROUND: This study compared the one-time success rate of blind and endoscopy-guided postpyloric feeding tube placement after implementing a comprehensive nursing scheme of intestinal blind placement for patients with ischemic stroke. METHODS: This retrospective cohort study included 179 patients with blind bedside placement and 118 with endoscopy-guided placement. The primary outcome was the one-time success rate of radiologically confirmed postpyloric placement. The secondary endpoints included the position of the tube tip, length of insertion, time of placement, and expenses. The safety endpoints were the incidence of complications caused by placement. RESULTS: The results showed that the method of tube placement did not significantly affect the outcome of the first tube placement (odds ratio [OR] = 0.41; 95% CI = 0.137-1.207; P = 0.105). Compared with endoscopy-guided placement, blind placement was half the cost. We also found that a history of abdominal surgery (OR = 0.003; 95% CI = 0.000-0.059; P < 0.001) and longer intensive care unit (ICU) days (OR = 0.94; 95% CI = 0.903-0.981; P = 0.004) were inversely associated with the one-time success rate. CONCLUSION: Our study suggested that blind intestinal feeding tube placement has an equivalent one-time success rate compared with endoscopy-guided placement in hospitalized patients with ischemic stroke if operators can be trained well. However, the expenses of endoscopy-guided placement were twice those of blind bedside methods. We also found that patients with abdominal surgery history and longer ICU stay were more likely to fail at the first placement. Further research is needed to replicate our single-center observations in a larger population of patients.

DNA Barcoding and Species Classification of Morchella.

True morels (Morchella) are a well-known edible fungi, with economically and medicinally important values. However, molecular identification and species taxonomy of the genus Morchella have long been controversial, due to numerous intermediate morphologies among species. In this study, we determined the identification efficiency of DNA barcoding and species classification of 260 individuals from 45 Morchella species, on the basis of multiple nuclear DNA markers. DNA barcoding analysis showed that the individual DNA fragment has a lower resolution of species identification than that of combined multiple DNA markers. ITS showed the highest level of species discrimination among the individual genetic markers. Interestingly, the combined DNA markers significantly increased the resolution of species identification. A combination of four DNA genes (EF1-α, RPB1, RPB2 and ITS) showed a higher species delimitation than that any combination of two or three markers. Phylogenetic analysis suggested that the species in genus Morchella could have been divided into two large genetic clades, the Elata Clade and Esculenta Clade lineages. The two lineages divided approximately 133.11 Mya [95% HPD interval: 82.77-197.95] in the early Cretaceous period. However, some phylogenetic species of Morchella showed inconsistent evolutionary relationships with the traditional morphological classifications, which may have resulted from incomplete lineage sorting and/or introgressive hybridization among species. These findings demonstrate that the interspecific gene introgression may have affected the species identification of true morels, and that the combined DNA markers significantly improve the resolution of species discrimination.

Ligand exchange engineering of FAPbI3 perovskite quantum dots for solar cells.

Formamidinium lead triiodide (FAPbI3) perovskite quantum dots (PQDs) show great advantages in photovoltaic applications due to their ideal bandgap energy, high stability and solution processability. The anti-solvent used for the post-treatment of FAPbI3 PQD solid films significantly affects the surface chemistry of the PQDs, and thus the vacancies caused by surface ligand removal inhibit the optoelectronic properties and stability of PQDs. Here, we study the effects of different anti-solvents with different polarities on FAPbI3 PQDs and select a series of organic molecules for surface passivation of PQDs. The results show that methyl acetate could effectively remove surface ligands from the PQD surface without destroying its crystal structure during the post-treatment. The benzamidine hydrochloride (PhFACl) applied as short ligands of PQDs during the post-treatment could fill the A-site and X-site vacancies of PQDs and thus improve the electronic coupling of PQDs. Finally, the PhFACl-based PQD solar cell (PQDSC) achieves a power conversion efficiency of 6.4%, compared to that of 4.63% for the conventional PQDSC. This work provides a reference for insights into the surface passivation of PQDs and the improvement in device performance of PQDSCs.

A transformed proportional-integral-derivative controller for a multi-vectored propeller aerostat with independent actuator magnitude and rate saturations.

The problem of designing a controller for a multi-vectored propeller airship with independent amplitude and rate saturations is addressed. First, a linear Proportional-Integral-Derivative (PID) controller is introduced for position control without considering the input saturations. Then, two design methods are applied to the traditional PID control output to satisfy the independent amplitude and rate constraints: the nested saturated PID controller (N-PID) and the transformed PID controller (T-PID). The bounded magnitudes and rate outputs of the modified controllers are given. Simulation results showed both controllers have good tracking performance while satisfying independent amplitude and rate saturations. However, the transformed PID controller has the advantage of expressing explicitly the relationship of the actuator magnitude and rate saturations with the parameters of the transformed function such that the actuator saturations are suppressed by calculation but not by trial and error.

Characterization of the complete mitochondrial genome of Morchella eohespera.

Morchella eohespera Beug, Voitk & O'Donnell is a typical black morel species. In this study, using the Nanopore sequencing platform, we characterized its whole mitochondrial (mt) genome sequence. Mt genome of M. eohespera is composed of circular DNA molecules of 243,963 bp, which encoded 102 protein-coding genes (PCGs), two ribosomal RNA genes (rRNA), and 31 transfer RNA (tRNA) genes. The base composition of M. eohespera mitogenome is as follows: A (30.40%), T (29.30%), G (20.8%), and C (19.5%). The phylogenetic analysis suggested that M. eohespera was closely related to the congeneric M. importuna.

Whole plastid genome of Anemone taipaiensis (Ranunculaceae), an endemic herb plant in China.

Anemone taipaiensis W. T. Wang is an endemic herb species in Shaanxi province (China). Here, we first characterized its whole plastid genome via pair-end sequencing method. The whole chloroplast genome was 156,659 bp in size, including a large single-copy (LSC) region of 78,439 bp, a small single-copy (SSC) region of 16,178 bp, and two repeat regions (IRs) of 31,021 bp. A total of 135 genes, including 91 protein-coding genes, 36 tRNA, and 8 rRNA genes were identified in A. taipaiensis. The phylogenetic analysis showed that A. taipaiensis have a close relationship with congeneric species A. trullifolia.

Characterization of the complete plastid genome of Acer tsinglingense, an endemic tree species in China.

Acer tsinglingense is an ecologically and economically important tree species in China. In this study, we characterized its whole plastid genome sequence using the Illumina sequencing platform. The complete plastid genome size of A. tsinglingense is 156,039 bp in length, including a large single-copy [LSC] region of 85,760 bp, a small single-copy [SSC] region of 18,139 bp, and a pair of inverted repeats [IRs] of 26,070 bp. The genome contains 137 genes, including 89 protein-coding genes, 40 tRNA genes, and 8 rRNA genes. The GC contents in chloroplast genome, LSC region, SSC region, and IR region were 38.0%, 36.2%, 32.4%, and 42.9%, respectively. The phylogenetic analysis based on the plastid genomes showed that A. tsinglingense was more closely related with the congeneric A. laevigatum, A. palmatum, A. wilsonii, and A. buergerianum, these species were clustered into a monophyletic clade with high bootstrap support.