120-GBaud 16-QAM silicon photonics IQ modulator for data center interconnection.

We demonstrated all-silicon IQ modulators (IQMs) operating at 120-GBaud 16-QAM with suitable bandwidth, and output power. We required optical signal-to-noise-ratio (rOSNR) that have promising potential to be used in 800-Gbps small-form-factor pluggable transceivers for data center interconnection. First, we tested an IQM chip using discrete drivers and achieved a per-polarization TX output power of -18.74 dBm and an rOSNR of 23.51 dB over a 100-km standard SMF. Notably, a low BER of 1.4e-3 was obtained using our SiP IQM chip without employing nonlinear compensation, optical equalization, or an ultra-wide-bandwidth, high-ENOB OMA. Furthermore, we investigated the performance of a 3D packaged transmitter by emulating its frequency response using an IQM chip, discrete drivers, and a programmable optical filter. With a laser power of 17 dBm, we achieved a per-polarization output power of -15.64 dBm and an rOSNR of 23.35 dB.

Lipidomic study and diagnosis of hepatocellular carcinoma tumor with rapid evaporative ionization mass spectrometry.

Liver cancer is generally considered the leading cause of cancer deaths worldwide, and hepatocellular carcinoma (HCC) contributes to more than 90% of liver cancers. The altered lipid metabolism for rapid cancer cell growth and tumor formation has been frequently proven. In this study, an ambient ionization mass spectrometry technique, rapid evaporative ionization mass spectrometry (REIMS) using a monopolar electric knife, called iKnife, was systematically optimized and employed for ex vivo analysis of 12 human HCC tumor tissue specimens together with the paired paracancerous tissue (PT) and noncancerous liver tissue (NCT) specimens. Nine free fatty acids and 34 phospholipids were tentatively identified according to their extract masses and/or tandem mass spectra. With the help of statistical methods, 7 free fatty acids and 10 phospholipids were distributed differently in 3 types of liver tissue specimens (95% confidence interval). The box plots showed these characterized lipid metabolites varied in PT, HCC, and NCT. Compared with PT and NCT, the upregulations of four common fatty acids FA 18:0, FA 20:4, FA 16:0, and FA 18:1, together with phospholipids PC 36:1, PE 38:3, PE (18:0/20:4), PA (O-36:1), PC (32:1), PC 32:0, PE 34:0, and PC (16:0/18:1), were found in HCC specimens. The sensitivity and specificity of the established statistic model for real-time HCC tumor diagnosis were 100% and 90.5%, respectively. This study demonstrated that the described REIMS technique is a potential method for rapid lipidomic analysis and characterization of HCC tumor tissue.

Surgery for Cronkhite-Canada syndrome complicated with intussusception: A case report and review of literature.

BACKGROUND: Cronkhite-Canada syndrome (CCS) is a rare nonhereditary disease with a syndrome of multiple gastrointestinal polyps, skin pigmentation, hair loss, and fingernail/toenail dystrophy. Intussusception is a serious condition with an occurrence rate of 5% in adults, which is mainly caused by intestinal tumors or other intestinal occupations. CASE SUMMARY: A 57-year-old woman was admitted to our hospital due to abdominal distension and pain for the past year. Her nausea and vomiting symptoms had been aggravated for the past month. Previous transoral enteroscopy results one year prior showed chronic erosive gastritis protuberans, duodenitis, and jejunitis. She had sparse body hair and brown pigmentation on the skin of her hands and bilateral anterior tibias. The nails of both hands were pale and lacked luster, and the fingernail of her ring finger was longitudinally cracked. Gastroscopy showed extensive diffuse polypoid lump changes in the gastric body and antrum, of 0.5-3 cm in size. Colonoscopy showed multiple polypoid mucosal bulges in the terminal ileum and multiple polyps (0.3-5 cm) throughout the colon. The patient was diagnosed with CCS and underwent partial excision of the polyps, but she refused hormone therapy. One month later, the patient complained of nausea and vomiting, accompanied by abdominal pain and inability to pass gas or stool. Contrast-enhanced computed tomography of the abdomen showed gastrointestinal polyposis and ileocecal intussusception. She underwent stomach and bowel surgery. CONCLUSION: CCS, as a rare disease with poor prognosis, should be treated aggressively. Systematic steroids, immunosuppressive agents, and biological agents were not applied; thus, the patient's symptoms quickly progressed, and intussusception occurred. She had to undergo surgery. Improved compliance may lead to a better prognosis.

Characteristics and potential malignancy of colorectal juvenile polyps in adults: a single-center retrospective study in China.

BACKGROUND: Colorectal juvenile polyps are rare and generally considered benign in adults. Carcinogenesis or neoplastic changes are rarely mentioned in the literature. We systematically evaluated the characteristics and potential malignancy of colorectal juvenile polyps in adults. METHODS: We retrospectively reviewed the medical records of 103 adults diagnosed with colorectal juvenile polyps from September 2007 to May 2020 at our hospital. The characteristics, endoscopic findings, occurrence of intraepithelial neoplasia, carcinogenesis and diagnostic value of chicken skin mucosa (CSM) were analyzed. RESULTS: The average age of patients with juvenile polyps was 43.2 years (range, 19 to 78 years). A total of 101 patients (101/103, 98.1%) had a single juvenile polyp, and two patients had multiple polyps (107 polyps in total). Polyp sizes ranged from 0.5 to 5 cm. One (1/107, 0.9%) juvenile polyp was cancerous, and 7 (7/107, 6.5%) developed low-grade intraepithelial neoplasia. Neoplasia and cancerization did not appear in the two patients with multiple polyps. A 27-year-old female had a 2-cm polyp with well-differentiated adenocarcinoma in the mucosa in the sigmoid colon with erosion on the surface. CSM was observed adjacent to 17 polyps, which were all located in the rectum and sigmoid colon, and one polyp showed low-grade intraepithelial neoplasia. CONCLUSIONS: Colorectal juvenile polyps occur in a wide range of locations and in variable sizes and numbers. These polyps are solitary in most patients and have neoplastic potential. CSM is not a tumorigenic marker in colorectal juvenile polyps and usually occurs in the distant colorectum. Colorectal juvenile polyps in adults may progress from low-grade intraepithelial neoplasia to high-grade intraepithelial neoplasia and then to carcinoma and should be treated when discovered and regularly followed as colorectal adenomas.

Idiopathic mesenteric phlebosclerosis associated with long-term oral intake of geniposide.

BACKGROUND: Idiopathic mesenteric phlebosclerosis (IMP) is a rare disease, and its etiology and risk factors remain uncertain. AIM: To investigate the possible influence of Chinese herbal liquid containing geniposide on IMP. METHODS: The detailed formula of herbal liquid prescriptions of all patients was studied, and the herbal ingredients were compared to identify the toxic agent as a possible etiological factor. Abdominal computed tomography (CT) and colonoscopy images were reviewed to determine the extent and severity of mesenteric phlebosclerosis and the presence of findings regarding colitis. The disease CT score was determined by the distribution of mesenteric vein calcification and colon wall thickening on CT images. The drinking index of medicinal liquor was calculated from the daily quantity and drinking years of Chinese medicinal liquor. Subsequently, Spearman's correlation analysis was conducted to evaluate the correlation between the drinking index and the CT disease score. RESULTS: The mean age of the 8 enrolled patients was 75.7 years and male predominance was found (all 8 patients were men). The patients had histories of 5-40 years of oral Chinese herbal liquids containing geniposide and exhibited typical imaging characteristics (e.g., threadlike calcifications along the colonic and mesenteric vessels or associated with a thickened colonic wall in CT images). Calcifications were confined to the right-side mesenteric vein in 6 of the 8 patients (75%) and involved the left-side mesenteric vein of 2 cases (25%) and the calcifications extended to the mesorectum in 1 of them. The thickening of colon wall mainly occurred in the right colon and the transverse colon. The median disease CT score was 4.88 (n = 7) and the median drinking index was 5680 (n = 7). After Spearman's correlation analysis, the median CT score of the disease showed a significant positive correlation with the median drinking index (r = 0.842, P < 0.05). CONCLUSION: Long-term oral intake of Chinese herbal liquid containing geniposide may play a role in the pathogenesis of IMP.

Hemosuccus pancreaticus caused by gastroduodenal artery pseudoaneurysm associated with chronic pancreatitis: A case report and review of literature.

BACKGROUND: Hemosuccus pancreaticus is a very rare but severe form of upper gastrointestinal hemorrhage. The most common etiology is peripancreatic pseudoaneurysm secondary to chronic pancreatitis. Due to the rarity of gastroduodenal artery pseudoaneurysms, most of the current literature consists of case reports. Limited knowledge about the disease causes diagnostic difficulty. CASE SUMMARY: A 39-year-old man with a previous history of chronic pancreatitis was hospitalized due to hematemesis and melena for 2 wk, with a new episode lasting 1 d. Two weeks prior, the patient had visited a local hospital for repeated hematemesis and melena. Esophagogastroduodenoscopy indicated hemorrhage in the descending duodenum. The patient was discharged after the bleeding stopped, but hematemesis and hematochezia recurred. Bedside esophago-gastroduodenoscopy showed no obvious bleeding lesion. On admission to our hospital, he had hematemesis, hematochezia, left middle and upper abdominal pain, severe anemia, and elevated blood amylase. After admission, intermittent hematochezia was observed. Abdominal contrast-enhanced computed tomography revealed a pseudoaneurysm in the pancreas head. Angiography confirmed the diagnosis of gastroduodenal artery pseudoaneurysm. The pseudoaneurysm was successfully embolized with a coil and cyanoacrylate. No bleeding was observed after the operation. After discharge from the hospital, a telephone follow-up showed no further bleeding signs. CONCLUSION: Hemosuccus pancreaticus caused by gastroduodenal artery pseudoaneurysm associated with chronic pancreatitis is very rare. This diagnosis should be considered when upper gastrointestinal bleeding and abdominal pain are intermittent. Abdominal enhanced computed tomography and angiography are important for diagnosis and treatment.

Low-complexity equalizer with a hybrid decision scheme for 50 Gb/s/λ PAM4-PON using a low-cost 10 G receiver.

In this Letter, we experimentally demonstrate a 50Gb/s/λ four-level pulse amplitude modulation-based passive optical network system with a 10 G class receiver. A memory polynomial equalizer (MPE) combined with a decision feedback equalizer (DFE) is applied to eliminate channel distortions in the system. To further improve the performance of the MPE-DFE, for the first time, to the best of our knowledge, a low-complexity hybrid decision scheme (HDS) is proposed, which consists of single-symbol decision (SSD) and multi-symbol decision (MSD). The SSD is exactly the conventional hard decision based on minimum Euclidean distance, whereas MSD is based on a simplified maximum likelihood detection principle with M-algorithm. In terms of complexity, MSD requires 19.1% more multiplications than SSD, but the symbol number of MSD only accounts for less than 20% of the total signal frame when the received optical power is greater than -27dBm. Experimental results show that the proposed MPE-DFE with HDS achieves a 0.7 dB and 1.3 dB sensitivity gain compared with conventional SSD, and up to 35.4 dB and 31.4 dB link power budget, regarding the forward error correction threshold of 10-2 and 10-3, respectively.

Multifocal gastrointestinal epithelioid angiosarcomas diagnosed by endoscopic mucosal resection: A case report.

BACKGROUND: Epithelioid angiosarcoma is a vascular neoplasm that is among the most aggressive subtypes of sarcomas. Its involvement in the gastrointestinal tract is rare. We here report a case of multifocal gastrointestinal epithelioid angiosarcomas presenting with gastrointestinal bleeding. CASE SUMMARY: A 77-year-old woman was admitted because of melena and dizziness for three months. Gastroscopy and colonoscopy were performed, revealing a centrally ulcerated hemorrhagic polypoid lesion in the gastric body and multiple polypoid lesions with blood clots and hemorrhagic tendency in the colon. Histopathological examination of routine endoscopic biopsy samples showed inflammation in the gastric mucosa and tubular adenomas in the colon. The polypoid lesions were removed by endoscopic mucosal resection. Immunohistochemistry suggested a final diagnosis of epithelioid angiosarcomas. The patient refused chemotherapy and died after three months. CONCLUSION: Epithelioid angiosarcomas are characterized by highly vascular nature and tendency to cause gastrointestinal bleeding. Efforts to obtain histological findings using endoscopic mucosal resection are of great importance.

User-specific power level allocation optimization for OFDM-NOMA in a multi-user RoF system.

In this Letter, we propose a digital signal processing (DSP) -aided technique to optimize the power ratio among users for orthogonal frequency division multiplexing (OFDM) -based non-orthogonal multiple access (NOMA) in an integrated optical fiber and millimeter wave (mmWave) wireless communication system. In this way, a central or distributed unit can leverage the proposed techniques to maintain the uniformity of the signal-to-noise ratios (SNRs) among subcarriers without requiring any channel information feedback. The proposed mechanism can facilitate the power allocation management by treating all subcarriers equally as an independent channel. As an illustration, multiple NOMA scenarios, in which a near user with 10 km fiber transmission and far user with either longer fiber distance or additional wireless propagation, are experimentally investigated. Experimental results demonstrate that when the conventional OFDM-NOMA without the proposed DSP-aided technique is used, the optimal power ratios vary rapidly when the subcarrier quality index changes due to high-frequency fading in a mmWave radio over fiber (RoF) system, whereas, by using the proposed techniques, including both orthogonal circulant matrix transform and discrete Fourier transform, the optimal power ratios on all effective subcarriers are optimized at the same level and the users' performance is significantly improved.

Diagnosis and management of a solitary colorectal juvenile polyp in an adult during follow-up for ulcerative colitis: A case report.

BACKGROUND: Juvenile polyps are the most common type of polyps in children but are rare in adults. Inflammatory bowel disease (IBD) patients have a similar spectrum of symptoms as patients with juvenile polyps. Both patients with juvenile polyps and those with active IBD have high fecal calprotectin levels. Four cases of children with ulcerative colitis (UC) with solitary juvenile polyps and one case of an adult with UC with juvenile polyposis syndrome have been reported upon diagnosis of UC, while there have been no cases of adults with UC with solitary juvenile polyp reported in the literature. CASE SUMMARY: A 37-year-old man with a 12-year history of UC was admitted to our clinic because of increased stool frequency. UC was diagnosed at the age of 25. As the lesion was confined to the rectum, sulfasalazine suppositories or mesalazine suppositories were used. The patient was followed in an outpatient clinic, and colonoscopy was performed every one or two years. The latest examination was undertaken three years prior in the presence of proctitis. Recently, the patient complained of three to five bowel movements a day. There was mucus in the stool but no visible blood. Colonoscopy revealed a solitary polyp, about 1.5 cm in diameter, with a short and broad peduncle in the transverse colon surrounded by congestive and edematous mucosa. The patient had no family history of colorectal polyps or cancer. The polyp was successfully removed by endoscopic mucosal resection. Histopathological examination revealed that the polyp was a juvenile polyp without any malignant signs. Immunohistochemical staining for p53 showed wild-type expression and p53 overexpression was not detected. Ki-67 labeling index was 3%. CONCLUSION: This is the first case of an adult UC patient with a solitary juvenile polyp at the 12-year follow-up. The correlation between juvenile polyps and the activity of IBD needs further study.

Synchronous colonic mucosa-associated lymphoid tissue lymphoma found after surgery for adenocarcinoma: A case report and review of literature.

BACKGROUND: Mucosa-associated lymphoid tissue (MALT) lymphoma is a subtype of non-Hodgkin lymphoma that is mainly involved in the gastrointestinal tract. The synchronous occurrence of colonic MALT lymphoma and adenocarcinoma in the same patient is extremely rare. We here report a case of synchronous colonic MALT lymphoma found on surveillance colonoscopy five months after surgery and chemotherapy for sigmoid adenocarcinoma. CASE SUMMARY: A 67-year-old man was admitted because of hematochezia for two months. Colonoscopy suggested a colonic tumor before hospitalization. Abdominal computed tomography (CT) revealed local thickening of the sigmoid colon. The patient underwent a left hemicolectomy with local lymph node dissection. The histopathology revealed moderately differentiated adenocarcinoma and partially mucinous adenocarcinoma. The pTNM stage was T3N1Mx. The patient received chemotherapy with six cycles of mFOLFOX6 after surgery. Colonoscopy was performed five months later and revealed single, flat, polypoid lesions of the colon 33 cm away from the anus. Subsequently, the patient underwent endoscopic mucosal resection for further diagnosis. The pathological diagnosis was MALT lymphoma. Positron emission tomography /CT suggested metastasis. The patient refused further treatment and died ten months later. CONCLUSION: Colonic MALT lymphoma may occur after surgery and chemotherapy for adenocarcinoma as a synchronous malignancy. Regular surveillance colonoscopy and careful monitoring after surgery are critical.

Isolation and Characterization of New Phenazine Metabolites with Antifungal Activity against Root-Rot Pathogens of Panax notoginseng from Streptomyces.

Three new phenazine metabolites, strepphenazine A-C (1-3), along with a known compound baraphenazine E 4 were isolated from the culture broth of a Streptomyces strain YIM PH20095. The structures were elucidated based on the spectral data. Compounds 1-4 showed different antifungal activity against Fusarium oxysporum, Plectosphaerella cucumerina, Alternaria panax, and Phoma herbarum, which caused root-rot disease of Panax notoginseng with minimal inhibitory concentrations (MICs) of 16-64 µg/mL; compared with compound 4, compounds 1-3 showed better antifungal activity against some of these pathogenic fungi with MICs of 16-32 µg/mL, while compound 4 showed antifungal activity against F. oxysporum, P. cucumerina, and A. panax with the same MICs of 64 µg/mL. Thus, strain YIM PH20095 provides new sources for the development of biological control agents to prevent the infection of pathogenic fungi of P. notoginseng.

Proactive real-time interference avoidance in a 5G millimeter-wave over fiber mobile fronthaul using SARSA reinforcement learning.

We propose and experimentally demonstrate a proactive real-time interference avoidance scheme using SARSA reinforcement learning (RL) in a millimeter-wave over a fiber mobile fronthaul system. The RL consists of three core factors, including state, action, and reward. The state is defined as a discretized value from the center frequency, the left, right, and center sub-EVM of the signal. We use five actions to shift the signal frequency in the proposed scheme, which is -20, -10, 0, 10, and 20 MHz, for the RL agent to choose the action to avoid the dynamic interference. For the agent to learn from the experience, the reward is defined as the log value of BER difference between the past and the present state. The RL-based approach is an online learning algorithm, which can learn in real time based on environmental feedback. Besides, the agent can learn from past experience owing to the Q-value table, which makes it act intelligently when facing a similar situation again. We verify the capability of the proposed scheme under both fixed and dynamic interference scenarios. The agent demonstrates an efficient intelligent mechanism to avoid the interference, which provides a promising solution for proactive interference mitigation in the 5 G mobile fronthaul network.

Non-iterative blind linearization algorithm for DML-based multi-IF-over-fiber mobile fronthaul systems.

We propose and experimentally demonstrate a novel digital post-linearization algorithm for the mobile fronthaul system employing bandwidth-efficient multiple intermediate frequency-over-fiber technology and a low-cost directly-modulated laser (DML). The proposed linearization algorithm is distinguished for blind adaption, the absence of training signal, or prior knowledge of the transmission channel. Particularly, it provides a closed-form solution for the estimation of optimal linearizer coefficients, leading to a non-iterative mode without convergence restrictions. In our experiments, one and nine 200 MHz 64-QAM OFDM IF signals (or channels) are transmitted over a 10 km single-mode fiber link using a DML. In both cases (one and nine IF channels), the linearization performance of the proposed algorithm is experimentally validated in terms of the reduction (>8 dB) of the adjacent channel leakage ratio, decrease (>10 dB) of error vector magnitude (EVM), and an increase (>9 dB) of EVM-compliant input RF power range.

Amycolatopsis panacis sp. nov., isolated from Panax notoginseng rhizospheric soil.

A novel Gram-positive bacterium, designated strain YIM PH21725T, was isolated from a sample of rhizospheric soil of Panaxnotoginseng cultivated in Anning, Yunnan. The strain contained meso-diaminopimelic acid in the cell-wall peptidoglycan. The main fatty acids identified were C17 : 0, iso-C15 : 0, iso-C16 : 0 and C16 : 0. The main menaquinone was MK-9 (H4). The polar lipids included phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol mannoside, phosphatidylinositol, phospholipids and phospholipids of an unidentified structure containing glucosamine. The G+C content of genomic DNA was 69.43 mol%. On the basis of its 16S rRNA gene sequence, strain YIM PH21725T should belong to the genus Amycolatopsis, and was closely related to Amycolatopsis sulphurea DSM 46092T (98.57 %), Amycolatopsis jejuensis JCM13280T (97.27 %), Amycolatopsis jiangsuensis KCTC 19885T (96.88 %) and Amycolatopsis ultiminotia JCM 16989T (96.8 %). The phenotypic, chemotaxonomic, phylogenetic and digital DNA-DNA hybridization results clearly indicated that strain YIM PH21725T represents a novel species of the genus Amycolatopsis, for which the name Amycolatopsispanacis sp. nov. is proposed. The type strain is YIM PH21725T (=CCTCC AA 2017044T=KCTC 49031T=DSM 105902T).

Pyrus pyrifolia fruit peel as sustainable source for spherical and porous network based nanocellulose synthesis via one-pot hydrolysis system.

In the present study, we attempted revalorization of pear (Pyrus pyrifolia L.) peel residue into high value-added nanomaterials. A green and facile one-pot isolation procedure was designed to simplify the isolation process of nanocellulose directly from pear peel residue. The one-pot approach employed in this work is interesting as the reaction involved less harmful chemicals usage and non-multiple steps. The reaction was carried out by adding hydrogen peroxide as an oxidant and chromium (III) nitrate as catalyst in the acidic medium under mild process conditions. FTIR spectroscopy proved that the pear peel derived nanocellulose was purely cellulose phases without the presence of non-cellulosic layer. XRD study indicated that the isolated nanocellulose possessed of cellulose I polymorph with high crystallinity index of 85.7%. FESEM analysis clearly revealed that the considerable size reduction during one-pot process. Remarkably, TEM analysis revealed that the isolated nanocellulose consisted of network-liked nature and spherical shaped morphologies with high aspect ratio of 24.6. TGA showed nanocellulose has lower thermal stability compared to pear peel residue. This study provided a cost-effective method and straightforward one-pot process for fabrication of nanocellulose from pear peel residue. This is the first investigation on the nanocellulose extraction from pear fruit.

Revalorization of selected municipal solid wastes as new precursors of "green" nanocellulose via a novel one-pot isolation system: A source perspective.

In the present work, four types of newly chosen municipal solid wastes (Panax ginseng, spent tea residue, waste cotton cloth, and old corrugated cardboard) were studied as the promising sources for nanocellulose, which has efficiently re-engineered the structure of waste products into highly valuable nanocellulose materials. The nanocellulose was produced directly via a facile one-pot oxidative hydrolysis process by using H2O2/Cr(NO3)3 solution as the bleaching agent and hydrolysis medium under acidic condition. The isolated nanocellulose products were well-characterized in terms of chemical composition, product yield, morphological structure and thermal properties. The study has found that the crystallinity index of the obtained nanocellulose products were significantly higher (62.2-83.6%) than that of its starting material due to the successive elimination of lignin, hemicellulose and amorphous regions of cellulose, which were in good agreement with the FTIR analysis. The evidence of the successful production of nanocellulose was given by TEM observation which has revealed the fibril widths were ranging from 15.6 to 46.2nm, with high cellulose content (>90%), depending on the cellulosic origin. The physicochemical properties of processed samples have confirmed that the isolation of high purity nanocellulose materials from different daily spent products is possible. The comparative study can help to provide a deep insight on the possibility of revalorizing the municipal solid wastes into nanocellulose via the simple and versatile one-pot isolation system, which has high potential to be used in commercial applications for sustainable development.

Investigation of optimal conditions for production of highly crystalline nanocellulose with increased yield via novel Cr(III)-catalyzed hydrolysis: Response surface methodology.

For the first time, a highly efficient Cr(NO3)3 catalysis system was proposed for optimization the yield and crystallinity of nanocellulose end product. A five-level three-factor central composite design coupled with response surface methodology was employed to elucidate parameters interactions between three design factors, namely reaction temperature (x1), reaction time (x2) and concentration of Cr(NO3)3 (x3) over a broad range of process conditions and determine the effect on crystallinity index and product yield. The developed models predicted the maximum nanocellulose yield of 87% at optimum process conditions of 70.6°C, 1.48h, and 0.48M Cr(NO3)3. At these conditions, the obtained nanocellulose presented high crystallinity index (75.3%), spider-web-like interconnected network morphology with the average width of 31.2±14.3nm. In addition, the yielded nanocellulose rendered a higher thermal stability than that of original cellulosic source and expected to be widely used as reinforcement agent in bio-nanocomposites materials.

Easy Fabrication of Highly Thermal-Stable Cellulose Nanocrystals Using Cr(NO3)3 Catalytic Hydrolysis System: A Feasibility Study from Macro- to Nano-Dimensions.

This study reported on the feasibility and practicability of Cr(NO3)3 hydrolysis to isolate cellulose nanocrystals (CNCCr(NO3)3) from native cellulosic feedstock. The physicochemical properties of CNCCr(NO3)3 were compared with nanocellulose isolated using sulfuric acid hydrolysis (CNCH2SO4). In optimum hydrolysis conditions, 80 °C, 1.5 h, 0.8 M Cr(NO3)3 metal salt and solid-liquid ratio of 1:30, the CNCCr(NO3)3 exhibited a network-like long fibrous structure with the aspect ratio of 15.7, while the CNCH2SO4 showed rice-shape structure with an aspect ratio of 3.5. Additionally, Cr(NO3)3-treated CNC rendered a higher crystallinity (86.5% ± 0.3%) with high yield (83.6% ± 0.6%) as compared to the H2SO4-treated CNC (81.4% ± 0.1% and 54.7% ± 0.3%, respectively). Furthermore, better thermal stability of CNCCr(NO3)3 (344 °C) compared to CNCH2SO4 (273 °C) rendered a high potential for nanocomposite application. This comparable effectiveness of Cr(NO3)3 metal salt provides milder hydrolysis conditions for highly selective depolymerization of cellulosic fiber into value-added cellulose nanomaterial, or useful chemicals and fuels in the future.

Endophytic fungi harbored in Panax notoginseng: diversity and potential as biological control agents against host plant pathogens of root-rot disease.

BACKGROUND: Endophytic fungi play an important role in balancing the ecosystem and boosting host growth. In the present study, we investigated the endophytic fungal diversity of healthy Panax notoginseng and evaluated its potential antimicrobial activity against five major phytopathogens causing root-rot of P. notoginseng. METHODS: A culture-dependent technique, combining morphological and molecular methods, was used to analyze endophytic fungal diversity. A double-layer agar technique was used to challenge the phytopathogens of P. notoginseng. RESULTS: A total of 89 fungi were obtained from the roots, stems, leaves, and seeds of P. notoginseng, and 41 isolates representing different morphotypes were selected for taxonomic characterization. The fungal isolates belonged to Ascomycota (96.6%) and Zygomycota (3.4%). All isolates were classified to 23 genera and an unknown taxon belonging to Sordariomycetes. The number of isolates obtained from different tissues ranged from 12 to 42 for leaves and roots, respectively. The selected endophytic fungal isolates were challenged by the root-rot pathogens Alternaria panax, Fusarium oxysporum, Fusarium solani, Phoma herbarum, and Mycocentrospora acerina. Twenty-six of the 41 isolates (63.4%) exhibited activity against at least one of the pathogens tested. CONCLUSION: Our results suggested that P. notoginseng harbors diversified endophytic fungi that would provide a basis for the identification of new bioactive compounds, and for effective biocontrol of notoginseng root rot.