Genomic analysis of Nypa fruticans elucidates its intertidal adaptations and early palm evolution.

Nypa fruticans (Wurmb), a mangrove palm species with origins dating back to the Late Cretaceous period, is a unique species for investigating long-term adaptation strategies to intertidal environments and the early evolution of palms. Here, we present a chromosome-level genome sequence and assembly for N. fruticans. We integrated the genomes of N. fruticans and other palm family members for a comparative genomic analysis, which confirmed that the common ancestor of all palms experienced a whole-genome duplication event around 89 million years ago, shaping the distinctive characteristics observed in this clade. We also inferred a low mutation rate for the N. fruticans genome, which underwent strong purifying selection and evolved slowly, thus contributing to its stability over a long evolutionary period. Moreover, ancient duplicates were preferentially retained, with critical genes having experienced positive selection, enhancing waterlogging tolerance in N. fruticans. Furthermore, we discovered that the pseudogenization of Early Methionine-labelled 1 (EM1) and EM6 in N. fruticans underly its crypto-vivipary characteristics, reflecting its intertidal adaptation. Our study provides valuable genomic insights into the evolutionary history, genome stability, and adaptive evolution of the mangrove palm. Our results also shed light on the long-term adaptation of this species and contribute to our understanding of the evolutionary dynamics in the palm family.

Flexible rotation of linear polarization conversion with a frequency selective surface.

A high-efficiency transmitted polarization converter based on a frequency selective surface (FSS) is proposed in this paper. The FSS-based polarization converter (FSS-PC) is designed based on receiving-via-transmitting (RVT) structure. The receiving and transmitting antenna structures are interconnected by the transmission line, designed in the form of metallized via holes. For any linearly polarized (LP) electromagnetic wave, our proposed FSS-PC has the capability to convert it into another LP electromagnetic wave. This converted wave will have a counterclockwise rotation angle of 2φ relative to the incident wave at 11 GHz. This is achieved by adjusting the relative azimuth φ between the polarization plane of the incident LP wave's electric field and the converter. Meanwhile, the FSS-PC can achieve exceptionally high polarization conversion above -0.30 dB at the central frequency of 11 GHz. Furthermore, as the azimuth of the incident electric field varies, this high-efficiency polarization conversion capability remains stable. The prototype has been fabricated and measured, and the measured results agree well with the simulated ones, thus confirming the effectiveness of the proposed design.

Synthesis of carboxymethyl cellulose-g-poly (acrylic acid-co-acrylamide)/polyvinyl alcohol sponge as a fast absorbent composite and its application in coral sand soil.

To improve the rapid absorption capacity of coral sand soil for rainfall, a composite of carboxymethyl cellulose-g-poly (acrylic acid-co-acrylamide)/polyvinyl alcohol sponge (CMC-g-P(AA-co-AM)/PVA) was designed and synthesized by coupling CMC-g-P(AA-co-AM) granules with a PVA sponge. The results showed that the rapid water absorption of CMC-g-P (AA-co-AM)/PVA in distilled water in 1 h was 26.45 g/g, twice that of CMC-g-P(AA-co-AM) and the PVA sponge, which is suitable for short-term rainfall. In addition, the cation had a slight influence on the water absorption capacity of CMC-g-P (AA-co-AM)/PVA, which were 29.5 and 18.9 g/g in 0.9 wt% NaCl and CaCl2 solutions, respectively, indicating the great adaptability of CMC-g-P (AA-co-AM)/PVA to high­calcium coral sand. With the addition of 2 wt% CMC-g-P (AA-co-AM)/PVA, the water interception ratio of the coral sand increased from 13.8 % to 23.7 %, and 54.6 % of the total interception water remained after 15-day evaporation. Moreover, pot experiments demonstrated that 2 wt% CMC-g-P(AA-co-AM)/PVA in coral sand enhanced plant development under water scarcity, suggesting that CMC-g-P (AA-co-AM)/PVA is a promising soil amendment for coral sand soils.

Applications of protein engineering in the microbial synthesis of plant triterpenoids.

Triterpenoids are a class of natural products widely used in fields related to medicine and health due to their biological activities such as hepatoprotection, anti-inflammation, anti-viral, and anti-tumor. With the advancement in biotechnology, microorganisms have been used as cell factories to produce diverse natural products. Despite the significant progress that has been made in the construction of microbial cell factories for the heterogeneous biosynthesis of triterpenoids, the industrial production of triterpenoids employing microorganisms has been stymied due to the shortage of efficient enzymes as well as the low expression and low catalytic activity of heterologous proteins in microbes. Protein engineering has been demonstrated as an effective way for improving the specificity, catalytic activity, and stability of the enzyme, which can be employed to overcome these challenges. This review summarizes the current progress in the studies of Oxidosqualene cyclases (OSCs), cytochrome P450s (P450s), and UDP-glycosyltransferases (UGTs), the key enzymes in the triterpenoids synthetic pathway. The main obstacles restricting the efficient catalysis of these key enzymes are analyzed, the applications of protein engineering for the three key enzymes in the microbial synthesis of triterpenoids are systematically reviewed, and the challenges and prospects of protein engineering are also discussed.

Separation and purification of plant terpenoids from biotransformation.

The production of plant terpenoids through biotransformation has undoubtedly become one of the research hotspots, and the continuous upgrading of the corresponding downstream technology is also particularly important. Downstream technology is the indispensable technical channel for the industrialization of plant terpenoids. How to efficiently separate high-purity products from complex microbial fermentation broths or enzyme-catalyzed reactions to achieve high separation rates, high returns and environmental friendliness has become the focus of research in recent years. This review mainly introduces the common separation methods of plant terpenoids based on biotransformation from the perspectives of engineering strain construction, unit separation technology, product properties and added value. Then, further attention was paid to the application prospects of intelligent cell factories and control in the separation of plant terpenoids. Finally, some current challenges and prospects are proposed, which provide possible directions and guidance for the separation and purification of terpenoids and even industrialization.

[Histological study on the safety of the controllable ileostomy with pipe].

OBJECTIVE: To investigate the safety of the controllable ileostomy with pipe in view of histology. METHODS: Twenty-eight Beagle dogs undergoing controllable ileostomy with pipe were studied. The special fistula tube with balloon was placed into the hole locating at the cecal root opposing the mesenteric side, and fixed by double knot compression method. RESULTS: The fistula tube was removed 14 days after surgery, then the safety of the procedure was preliminarily evaluated by gastrointestinal radiography and anatomical observation. The small intestine tissue at the compression suture was used as the experimental segment, and the small intestine tissue at the proximal non-compression suture was used as the control segment. The histological staining and the immunohistochemical staining of S-100 protein, c-kit protein and α-smooth muscle actin(α-SMA) protein between two segment were compared, while quantitative comparison of myenteric plexus, intestinal Cajal cell(ICC) and smooth muscle cells in intestinal wall was carried out. After removal of fistula tube at 14 days postoperative, the dogs were normal in feeding and defecation. The digestive tract radiography showed that the intestine was patent without obvious stenosis and obstruction. The dogs were dissected 21 days after operation. The abdominal sinus ostium was well healed and the internal sinus was well formed. Under gross inspection, blood supply, morphology and motor function of experimental intestine segment were similar from the proximal and distal segments of control intestine. S-100 immunohistochemical staining showed that the morphology and distribution of S-100 protein positive cells and "blank area" cells in the experimental and control segments were consistent. Myenteric plexus counting showed that the experimental segment was 3.62±1.82/field and the control segment was 3.27±1.62/field, whose difference was not statistically significant(t=1.30, P=0.20). Immunohistochemical staining of c-kit showed that the distribution of c-kit positive cells in both segments was consistent. Counting of the number of ICCs in myenteric plexus revealed that experimental segment was 2.96±2.57/plexus, and control segment was 2.49±1.80/plexus without significant difference(t=1.81, P=0.07). Immunohistochemical staining of α-SMA showed that the morphology and distribution of smooth muscle cells in whole intestinal wall(muscle layer, longitudinal muscle, ring muscle) in experimental and control segments were consistent. The average absorbance(A) value of α-SMA staining in ring muscle layer was detected and quantified. The experimental segment was 0.15±0.03 and control segment was 0.14±0.04 without significant difference(t=1.16, P=0.25). CONCLUSION: The technique of controllable ileostomy with pipe is safe in view of histology, which may replace the traditional protective ileostomy.

[Expression of transcriptional coactivator with PDZ-binding motif (TAZ) in colon cancer tissues and its clinical significance].

OBJECTIVE: To investigate the expression of transcriptional coactivator with PDZ-binding motif(TAZ) in colon cancer tissues and its association with clinicopathological parameters and prognosis of patients. METHODS: The expression of TAZ protein was detected in 56 resected colon cancer tissues and matched tumor-adjacent tissues using immunohistochemistry. The positive expression rate of TAZ was compared between patients with different clinicopathological features. The association between TAZ expression and prognosis was analyzed. RESULTS: Expression of TAZ protein located in the nucleolus. The positive expression rate of TAZ in colon cancer tissues was significantly higher than that in matched tumor-adjacent tissues(73.2% vs. 12.5%, P=0.000). Clinicopathological evaluation suggested that the expression of TAZ protein was associated with tumor size(P=0.009), depth of infiltration(P=0.026), lymph node metastasis (P=0.007) and TNM staging(P=0.004). Colon cancer patients with negative expression of TAZ showed a better 5-year survival as compared with those with positive expression of TAZ (66.7% vs. 22.9%, P=0.0017). Multivariate Cox regression analysis revealed that positive TAZ expression was an independent factor for predicting poor prognosis in colon cancer (HR:3.532, 95% CI: 1.3-9.9, P=0.016). CONCLUSION: The expression of TAZ protein is up-regulated in colon cancer tissues and its high expression is associated with poor prognosis of colon cancer patients.

[Comparison of short- and long-term efficacy of three procedures in postoperative digestive tract reconstruction for upper gastric cancer].

OBJECTIVE: To compare the short- and long-term efficacy of three different procedures used for digestive tract reconstruction after radical gastrectomy for upper gastric cancer. METHODS: Clinical data of 191 patients with upper gastric cancer undergoing radical gastrectomy in the Fujian Provincial Hospital between January 2000 and December 2012 were analyzed retrospectively. Surgical procedures were classified as total gastrectomy followed by Roux-en-Y esophagojejunostomy (TG-RY, n=123), proximal gastrectomy followed by esophagogastrostomy (PG-EG, n=40), and proximal gastrectomy followed by jejunal interposition (PG-JI, n=28). Clinicopathological characteristics, perioperative and long-term outcomes were compared among the three groups. RESULTS: The operative time was shorter (178 vs. 248 and 224 min, P<0.05), and the intraoperative blood loss was less (194 vs. 323 and 265 ml, P<0.05) in PG-EG group than those in TG-RY and PG-JI groups. Early postoperative complications and hospital stay were comparable (both P>0.05). With respect to gastrectomy-associated symptoms, reflux and heartburn were more frequent in PG-EG patients, while dumpling syndrome was more frequent after TG-RY. Postoperative weight loss was not significantly different among three procedures (P>0.05), however, hemoglobin and serum albumin levels were lower in TG-RY patients (both P<0.05). The 5-year survival rate was similar (P>0.05). CONCLUSIONS: Surgeons need to choose the proper procedure according to tumor features and patient condition. PG-JI should be the first choice in terms of fewer complaints and better nutrition. TG-RY tends to be used for larger and more advanced tumors. PG-EG is the most minimally invasive procedure and thus may be suitable for older and high-risk patients.

[Expression of miR-146a in colon cancer and its significance].

OBJECTIVE: To investigate miR-146a expression in colonic cancer and its clinical implications. METHODS: Quantitative real-time PCR was employed to detect the levels of miR-146a expression in colonic cancer tissues, pair-matched adjacent normal tissues and different colonic cancer cell lines. MTT essay was used to evaluate the proliferation of colonic cancer SW260 cells transfected with miR-146a mimics, and the cell cycle and apoptosis of the cells were analyzed with flow cytometry. RESULTS: Compared with the normal tissues, 38 of the 43 colonic cancer samples showed down-regulated miR-146a expression, which was associated with poor tumor differentiation. The expression of miR-146a in the tumor tissues was significantly correlated with tumor size and clinical stages. The patients with high miR-146a expression levels had significantly longer total survival time than those with low expression of miR-146a. In SW260 cell cultures, transfection with miR-146a mimics significantly inhibited cell growth (P<0.05) and increased the cell apoptosis rate (11.9% vs 5.9%) but produced no obvious effect on cell cycle. CONCLUSIONS: miR-146a may serve as a potential therapeutic target for colonic cancer for its role in inhibiting colonic cancer cell proliferation.

[Pattern of lymph node metastasis and extent of lymphadenectomy for distal gastric cancer].

OBJECTIVE: To analyze lymph node (LN) metastasis patterns and determine the appropriate extent of LN dissection in distal-third gastric cancer. METHODS: Clinical data of 545 patients with distal third gastric cancer undergoing radical operation in the Fujian Provincial Hospital between 2001 and 2010 were analyzed retrospectively. The metastasis rate for each LN station was analyzed stratified by the depth of tumor invasion. RESULTS: The incidence of LN metastasis in this cohort was 38.2% (208/545). LN metastasis rate in mucosal cancer was 2.0% (2/99) and involved LNs were limited to station 1 LN stations. LN metastasis rate in submucosal cancer was 18.9% (18/95), significantly higher than that in mucosal cancer (P<0.01). The metastasis rates to groups No.7, 8 and 9 in station 2 were 5.3% (5/94), 3.2% (3/94), and 1.1% (1/89) respectively. In addition, 3 cases (3.2%) had metastasis in station 2 outside the range of groups 7, 8 and 9 including groups No.1, 11p and 12. Gastric cancer invading the muscularis propria or deeper layers showed an significant increased rate of metastasis (P<0.01). CONCLUSION: D1 dissection seems to be sufficient for mucosal cancer. Standard D2 dissection should be performed for cancers of the muscularis propria or deeper. For submucosal cancer, an extended D1+ dissection is required for complete removal of metastatic nodes.