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Driving Miss Norma : one family's journey saying \yes\ to living /
\"When Miss Norma was diagnosed with uterine cancer, she was advised to undergo surgery, radiation, and chemotherapy. But instead of confining herself to a hospital bed for what could be her last stay, Norma--newly widowed after nearly seven decades of marriage--rose to her full height of five feet and told her doctor, 'I'm ninety years old. I'm hitting the road.' Packing what she needed, Norma took off on an unforgettable cross-country journey with three professional nomads--her retired son Tim, his wife Ramie, and their standard poodle Ringo--in a thirty-six-foot RV\"-- Provided by publisher.
Book
Process optimization and comprehensive utilization of recyclable deep eutectic solvent for the production of ramie cellulose fibers
Deep eutectic solvents (DESs) are emerging green chemical reagents, most of which are nontoxic, biodegradable, environmentally friendly, and easy to access. DESs constituted of choline chloride and urea has been proved to be an innovative method for ramie cellulose fibers extraction. However, the costly DESs reagent and inefficient solvent recovery are still challenging for wide application. Here, the optimal extraction conditions and the possibility of DESs solvent recovery were investigated. Specifically, the effect of incremental reuse times of degumming solution on surface morphology, chemical composition, cellulose crystallinity (65.69 ~ 70.11%), thermal stability (thermal decomposition temperature 353 ~ 356℃), degree of polymerization (1679 ~ 2445), and mechanical tenacity of degummed fibers were systematically evaluated. The results showed that reusable degumming solution could still remove the majority of non-cellulosic components from raw ramie, even after four times repeating degumming. The treated fibers achieved the cellulose content of above 90.21%, fiber yield of 74.16 ~ 78.55%, density of 6.30 ~ 7.87 dtex, tenacity of 5.21 ~ 6.72 cN/dtex, respectively. All these mechanical properties fulfilled the requirement of spinning process. Moreover, the insoluble lignin and polysaccharides were successfully separated from degumming solution and the DESs solvent was recycled with ease, beneficially realizing recycle economy and sustainable development for natural fiber extraction.
Journal Article
Choline chloride-based deep eutectic solvent systems as a pretreatment for nanofibrillation of ramie fibers
As a new type of green solvents, deep eutectic solvents (DESs) were used as pretreatment media for the nanofibrillation of ramie fibers (RFs). Two DESs, choline chloride-oxalic acid dihydrate (CO) and choline chloride-urea (CU), were formed at 100 °C and then applied to decompose RFs. The DES-pretreated fibers were nanofibrillated using a planetary ball mill, and their properties were analyzed. During the DES pretreatment, CU DES could only dissolve some of hemicelluloses in raw RFs, while CO DES could degrade some oligosaccharides and a part of amorphous cellulose to loosen the fiber structure. Therefore, only the CO DES pretreatment could significantly enhance nanofibrillation of the RFs with a low hemicellulose content in this study, as indicated by the decrease of milling time (from 11 to 5 h) to obtain desirable cellulose nanofibrils (CNFs). After 7 h CO DES pretreatment at room temperature and a subsequent ball milling process, a turbid and gel-like CNF suspension with a mean equivalent spherical diameter of 262 nm was obtained from RFs, and the mass yield of CNFs reached 94.06%. The CNFs also showed a crystallinity index of 66.51% and a thermal stability with
T
max
= 322.6 °C, and the produced CNF film had a tensile strength of 52 MPa. Overall, the CO DES pretreatment has great potential for use in the production of CNFs from RFs.
Graphical abstract
Journal Article
Morpho-physiological traits, antioxidant capacity and phytoextraction of copper by ramie (Boehmeria nivea L.) grown as fodder in copper-contaminated soil
Ramie (
Boehmeria nivea
L.), the oldest fiber crop in China, can also be grown as fodder crop because of its huge biomass production. Moreover, it has the potential to colonize heavy metal–contaminated soils which showed the possibilities of phytoremediation using
B. nivea.
Therefore, the present study was conducted to investigate the potential of
B. nivea
for phytoextraction of copper (Cu)-contaminated soil. Moreover, the impact of different concentrations of Cu on growth and antioxidant enzymatic activity by
B. nivea
were also studied. For this purpose, a pot experiment was conducted to examine the growth, antioxidative response, and localization (distribution) of Cu in
B. nivea
plant under different Cu concentrations (0, 50, 100, 200, 300, and 400 mg kg
−1
soil). Results revealed that
B. nivea
tolerated up to 100 mg kg
−1
Cu concentration without a significant decrease in biomass, but further increase in Cu concentration from 200 to 400 mg kg
−1
exhibited a significant reduction in chlorophyll content, fresh and dry biomass, plant height, and number of leaves. It was further observed that
B. nivea
accumulated more Cu in roots (26 to 53 mg kg
−1
), followed by the leaves (23 to 28 mg kg
−1
) and stems (14 to 21 mg kg
−1
), while the values for both bioaccumulation factor (BAF) and translocation factor (TF) at all treatments were less than 1. Moreover, activities of antioxidative enzymes (superoxide dismutase and peroxidase) were initially increased with the exposure of 50, 100, and 200 mg kg
−1
Cu, but decreased by further increasing the Cu concentration to 300 and 400 mg kg
−1
indicating the oxidative stress which is manifested by high
malondialdehyde
(MDA) and proline contents also. Thus, based on results, it can be concluded that
B. nivea
accumulated relatively low Cu contents in aboveground parts and could be grown as fodder crop for phytoremediation of Cu-contaminated sites.
Journal Article
Mechanical properties of ramie/flax hybrid natural fiber composites under different conditions
Hybrid ramie/flax natural fiber reinforcement along with epoxy resin is used as the matrix material in this research. Compression molding was adopted as the fabrication method. Ramie/flax at 40 wt. % and 1 cm fiber length showed a better tensile strength of 32.67 MPa than other combinations. Hybrid fiber combination from 30 to 40 wt. % created a strong compatibility between fiber/matrix phase and improved stress transfer behavior along with elastic deformation. Flexural strength results showed enhancement from 43.75 to 52.47 MPa with fiber addition and varying fiber length up to 40 wt. % and 0.5 cm. Impact strength of the hybrid combinations increased from 10.23 to 15.97 kJ/m
2
. A 5 % NaOH treatment had significant tensile properties varying from 28.42 to 32.67 MPa compared to untreated and 8 % surface treated fibers. Alkali treatment a revealed 49.83–52.47 MPa and 49.12–49.99 MPa flexural strength. Maximum tensile strength of 33.46 MPa was observed under a combination of 120 °C temperature, 12 MPa pressure, and 7 min duration. High pressure, high operating temperature and time, lead to a decline in the mechanical properties of the polymer composites. The SEM analysis showed that the combination with 40 wt. % natural fiber had good fiber distribution leading to better properties. Research works dealing with natural fiber addition, fabrication conditions, and surface treatments are rare.
Journal Article
Total RAMIE with three-field lymph node dissection by a simultaneous two-team approach using a new docking method for esophageal cancer
BackgroundThoracic esophageal cancer surgery using robotic approaches for the thoracic and abdominal parts has recently been reported as total robot-assisted minimally invasive esophagectomy (RAMIE). We herein present the first report of a new technique for esophageal cancer: total RAMIE with three-field lymph node dissection (3FLND) by a simultaneous two-team approach using a new docking method.MethodsWe reviewed 20 patients who underwent total RAMIE with 3FLND by a simultaneous two-team approach at the National Cancer Center East Hospital from March 2023 to September 2023. Short-term surgical outcomes and the safety and efficacy of this technique were analyzed.ResultsThe mean operative time for abdominal surgery with this new docking technique was 135 ± 19.6 min. The total operative time was 488 ± 42.9 min, and the time from the end of abdominal manipulation to the end of surgery was 80.1 ± 15.6 min. The intraoperative blood loss was 116.7 ± 64.4 mL. The incidence of anastomotic leakage, postoperative vocal cord paralysis, and postoperative pneumonia was 10%, 5%, and 10%, respectively. The median postoperative hospital stay was 14 days (range 11–63 days). No in-hospital deaths occurred, and R0 resection was possible in all cases. The average number of lymph nodes dissected was 87.7.ConclusionThese results demonstrate that total RAMIE with a simultaneous two-team approach using the new docking method can be safely introduced. The simultaneous cervical and abdominal manipulation with the new docking method allowed total RAMIE without prolonging the operating time, suggesting that it may be a valuable approach for esophageal cancer surgery.
Journal Article
Isolation and characterization of cellulosic fibers from ramie using organosolv degumming process
Degumming bast fibers by organic solvents has been a promising method in recent years due to easy recovery and reuse of organic solvents. In this research, the possibility of ramie fiber degumming by glycol and a combination of acetic acid with glycol was studied, in which two steps were involved in the degumming process: distilled water boiling pretreatment and organosolv treatment by a combination of glycol/acetic acid (100/0, 90/10, 80/20, 70/30, 60/40, 50/50). Results displayed that the pretreatment could remove 6.99% of hemicellulose, 0.59% of lignin and 36.26% of other gums compared with raw ramie. While with organosolv treatment (130 °C, 6 h), fibers treated by glycol/acetic acid (50/50) had the best effect of removing gums. The hemicellulose and lignin content of fibers reduced by 44.81% and 54.12%, respectively (compared with raw ramie), while the residual gum content still failed to meet the requirements of spinning process. Besides, the tenacity of glycol/acetic acid treated fibers was lower than that of only glycol treated fibers (4.67 cN/dtex). Considering that the addition of acid could cause a decrease in fiber tenacity, the step of organosolv (only glycol) treatment was optimized by altering the degumming condition. The tenacity, linear density, non-cellulosic component ratio of fibers treated with the optimized condition (200 °C, 80 min) were 6.53 cN/dtex, 6.06 dtex, 5.78%, respectively, which met the needs of industrial production. Compared with the organosolv treated fibers, these properties of fibers with traditional alkaline treatment were better, but the yield (62.4%) was much lower than that of fibers treated with glycol in two degumming condition (77–82%). Considering impressive properties of the treated ramie, the method of organosolv degumming with high degumming efficiency and environmental protection would bring an innovative thought for natural fiber isolation.Graphic abstract
Journal Article
Fabrication of highly efficient flame-retardant and biocompatible ramie fabrics through covalent bonding and layer-by-layer assembly methods
Ramie fibers have poor flame-retardant properties, which limits their application. To improve the flame-retardant properties of ramie fabric (RF), a durable flame-retardant coating was successfully realized on RF by combining covalent bonding and electrostatic adsorption. Si/P/N flame-retardant coatings were constructed on RF using cationic polyethyleneimine (PEI) and anionic sodium hexametaphosphate (PSP) via the layer-by-layer (LBL) assembly approach with the introduction of 3-glycidoxypropyltrimethoxysilane (GPTMS) as an organic cross-linker. Compared with the untreated RF samples, the fabrics treated with the flame-retardant coating PEI/PSP via the LBL method presented reductions of 51.06%, 48.30%, and 40.05% in the fire growth rate, peak heat release rate, and total heat release, respectively, in the cone calorimeter test. In addition, at a weight gain of 31.57%, the fabric self-extinguished in the UL-94 test within 10 s after leaving the ignition source, resulting in a damaged length of 6.13 cm. G-3 retained the limiting oxygen index (LOI) of 26.40% after 6 laundering cycles (LCs). The TG results revealed that the char residue of G-3 at 800 °C reached 30.34 wt%. The surface of the flame-retardant coating of GPTMS-PEI/PSP had good char formation. This study provides a feasible method for realizing durable flame-retardant RFs.
Journal Article
Cationic modification of ramie fibers in liquid ammonia
Anhydrous liquid ammonia was used as a solvent for the cationic modification of ramie fiber using 2, 3-epoxypropytrimethylammonium chloride (EPTAC). The processing parameters, including treatment temperature, treatment time, concentration of EPTAC, and concentration of NaOH were schematically investigated in order to control the properties of the fibers. The optimum parameters for cationic modification in liquid ammonia were analyzed through zeta potential measurement. The modified fibers were dyed in different conditions after modification, and the dyeing behaviors such as exhaustion and fixation properties were carefully examined. The modified fiber in liquid ammonia consisted of a higher number of cationic groups on the fibers compared to the fibers modified in water. The cationization reaction in liquid ammonia significantly decreased the crystallinity and the crystallite orientation of the resultant fibers. The decreased crystallinity slightly decreased the thermal resistance and tensile strength but increased the elongation ability of the fibers. The liquid ammonia cationic modification process turned the appearance of fibers from rough to smooth and lustrous due to swelling of fibers in the solvent. The exhaustion, fixation and wash fastness property of the fibers were improved after the cationic modification in liquid ammonia.
Graphical Abstract
Journal Article
Cloning, evaluation, and high-level expression of a thermo-alkaline pectate lyase from alkaliphilic Bacillus clausii with potential in ramie degumming
Alkaline pectate lyases (Pels) have potential application in bioscouring of the textile industry. In this study, a thermo-alkaline Pel (BacPelA) gene from an alkaliphilic
Bacillus clausii
strain was cloned and overexpressed in
Escherichia coli
. The mature BacPelA exhibited maximum activity at pH 10.5 and 70 °C and showed high cleavage capability on methylated pectins. BacPelA showed the highest specific activity of 936.2 U mg
−1
on ≥85% methylated pectin and 675.5 U mg
−1
on standard substrate polygalacturonic acid (PGA) upon evaluation of the absorbance at 235 nm (A
235
). The
K
m
and
k
cat
values for PGA were 0.54 g l
−1
and 346.5 s
−1
, respectively. Moreover, the 3,5-dinitrosalicylic acid (DNS) assay, which detects the released reducing oligogalacturonic acids, was confirmed to be inaccurate and unsuitable for endo-acting pectinase activity assay because of the difference in the reducibility by DNS reagent between the standard galacturonic acid and the catalytic oligomer products. Significant ramie fiber weight loss was observed following treatment with BacPelA (24.8%) and combined enzyme-chemical method (30.9%), which indicated that the degumming efficiency of BacPelA was the highest of all alkaline and thermostable Pels reported to date. The total activity of the recombinant mature BacPelA reached 8378.2 U ml
−1
(A
235
) by high-cell-density cultivation in fed-batch fermentation with productivity of 239.4 U ml
−1
h
−1
using
E. coli
as host, which represents the highest Pel yield reported to date. Therefore, BacPelA, with promising properties for bioscouring, shows potential applications for ramie degumming in the textile industry.
Journal Article