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1.
Med Phys ; 2024 Mar 18.
Article in English | MEDLINE | ID: mdl-38497549

ABSTRACT

BACKGROUND: The scaphoid is an important mechanical stabilizer for both the proximal and distal carpal columns. The precise estimation of the complete scaphoid bone based on partial bone geometric information is a crucial factor in the effective management of scaphoid nonunion. Statistical shape model (SSM) could be utilized to predict the complete scaphoid shape based on the defective scaphoid. However, traditional principal component analysis (PCA) based SSM is limited by its linearity and the inability to adjust the number of modes used for prediction. PURPOSE: This study proposes an iterative kernel principal polynomial shape analysis (iKPPSA)-based SSM to predict the pre-morbid shape of the scaphoid, aiming at enhancing the accuracy as well as the robustness of the model. METHODS: Sixty-five sets of scaphoid images were used to train SSM and nine sets of scaphoid images were used for validation. For each validation image set, three defect types (tubercle, proximal pole, and avascular necrosis) were virtually created. The predicted shapes of the scaphoid by PCA, PPSA, KPCA, and iKPPSA-based SSM were evaluated against the original shape in terms of mean error, Hausdorff distance error, and Dice coefficient. RESULTS: The proposed iKPPSA-based scaphoid SSM demonstrates significant robustness, with a generality of 0.264 mm and a specificity of 0.260 mm. It accounts for 99% of variability with the first seven principal modes of variation. Compared to the traditional PCA-based model, the iKPPSA-based scaphoid model prediction demonstrated superior performance for the proximal pole type fracture, with significant reductions of 25.2%, 24.7%, and 24.6% in mean error, Hausdorff distance, and root mean square error (RMSE), respectively, and a 0.35% improvement in Dice coefficient. CONCLUSION: This study showed that the iKPPSA-based SSM exploits the nonlinearity of data features and delivers high reconstruction accuracy. It can be effectively integrated into preoperative planning for scaphoid fracture management or morphology-based biomechanical modeling of the scaphoid.

2.
Nagoya J Med Sci ; 85(3): 465-475, 2023 Aug.
Article in English | MEDLINE | ID: mdl-37829476

ABSTRACT

We aimed to explore the correlations of high molecular weight adiponectin (HMW-ADP), tumor necrosis factor-alpha (TNF-α) and vascular endothelial growth factors (VEGFs) with the occurrence of colonic polyps in the prediabetic population. Two hundred patients with prediabetes were enrolled, and their clinical data were retrospectively analyzed. They were divided into group A (75 patients with colonic polyps) and group B (125 patients without colonic polyps). Eighty patients with normal glucose tolerance in the same period were divided into group C (32 patients with normal glucose tolerance and colonic polyps) and group D (48 patients with normal glucose tolerance but no colonic polyps). The correlations of serum HMW-ADP, TNF-α and VEGF levels with plasma glucose and insulin levels were explored by Pearson's analysis. The factors influencing the occurrence of colonic polyps were determined by logistic regression analysis. Serum HMW-ADP was negatively correlated with TNF-α, VEGFs, FPG, 2hPG, FI and HOMA-IR (r<0, P<0.05), whereas serum TNF-α and VEGFs were positively correlated with FPG, 2hPG, FI and HOMA-IR (r>0, P<0.05). Age, body mass index, waist-to-hip ratio, history of smoking, history of drinking, family history of colon cancer, TNF-α and VEGF were independent risk factors [odds ratio (OR)>1, P<0.05], and HMW-ADP was a protective factor (OR<1, P<0.05). The areas under the curves of serum HMW-ADP, TNF-α, VEGFs and their combination for predicting the occurrence of colonic polyps were 0.899, 0.787, 0.908 and 0.922, respectively. The combination of HMW-ADP, TNF-α and VEGFs can effectively predict the occurrence of colonic polyps in prediabetic patients.


Subject(s)
Colonic Polyps , Insulin Resistance , Prediabetic State , Humans , Tumor Necrosis Factor-alpha , Vascular Endothelial Growth Factor A , Prediabetic State/epidemiology , Adiponectin , Colonic Polyps/epidemiology , Molecular Weight , Retrospective Studies , Glucose
3.
Front Bioeng Biotechnol ; 11: 1229218, 2023.
Article in English | MEDLINE | ID: mdl-37609110

ABSTRACT

Background: Posterior internal fixation is the main method used for the treatment of thoracolumbar fractures. Fractures often occur in the upper 1/3 of the vertebral body. However, they can also occur in the middle or lower 1/3 of the vertebral body. At present, there is no report discussing the potential effects of sagittal location on instrument biomechanics or surgical strategy. The object of this study was to investigate the effect of the sagittal location of the fracture region of the vertebral body on the biomechanics of the internal fixation system and surgical strategy. Methods: A finite element model of the T11-L3 thoracolumbar segment was established based on a healthy person's CT scan. Different sagittal fracture location finite element models were created by resection of the upper 1/3, middle 1/3, and lower 1/3 of the L1 vertebral body. Three surgical strategies were utilized in this study, namely, proximal 1 level and distal 1 level (P1-D1), proximal 2 level and distal 1 level (P2-D1), and proximal 1 level and distal 2 levels (P1-D2). Nine fixation finite element models were created by combining fracture location and fixation strategies. Range of motion, von Mises stress, and stress distribution were analyzed to evaluate the effects on the instrument biomechanics and the selection of surgical strategy. Results: In all three different fixation strategies, the maximum von Mises stress location on the screw did not change with the sagittal location of the fracture site; nevertheless, the maximum von Mises stress differed. The maximum rod stress was located at the fracture site, with its value and location changed slightly. In the same fixation strategy, a limited effect of sagittal location on the range of motion was observed. P2D1 resulted in a shorter range of motion and lower screw stress for all sagittal locations of the fracture compared with the other strategies; however, rod stress was similar between strategies. Conclusion: The sagittal location of a fracture may affect the intensity and distribution of stress on the fixation system but does not influence the selection of surgical strategy.

4.
Biomed Tech (Berl) ; 68(6): 573-582, 2023 Dec 15.
Article in English | MEDLINE | ID: mdl-37462669

ABSTRACT

OBJECTIVES: Tunnel enlargement and graft failure are common complications associated with ACL reconstruction. The mechanical interaction between the graft and the tunnel aperture may play a more important role. This study aims to evaluate graft position within femoral tunnel and the graft force under external loads. METHODS: An FE model of the femur-graft-tibia complex was constructed from CT images of an anatomically reconstructed knee specimen. The model was subjected to kinematics of passive flexion extension, anterior/posterior translation, internal/external rotation and valgus kinematics, which were collected from experimental testing. Graft shift and rotation of graft-tunnel contact region during flexion/extension and external loadings were recorded and compared to experimental measurements. RESULTS: Model showed that the graft shifted in the femoral tunnel during flexion and under external loads. The graft-tunnel contact area rotated by up to 55° during flexion from full extension to 90° of extension implying that the so-called "wiper effect" occurs during most of flexion angles. CONCLUSIONS: Different regions of the femoral tunnel aperture, particularly the anterior region, were under significantly more contact force from the graft than other areas of the aperture during the anterior translation test, potentially leading to femoral tunnel enlargement to the anterior side of the aperture.


Subject(s)
Anterior Cruciate Ligament Reconstruction , Anterior Cruciate Ligament , Humans , Anterior Cruciate Ligament/surgery , Anterior Cruciate Ligament Reconstruction/methods , Knee Joint/surgery , Femur/surgery , Biomechanical Phenomena , Range of Motion, Articular , Computer Simulation , Cadaver
5.
Carbohydr Polym ; 315: 120983, 2023 Sep 01.
Article in English | MEDLINE | ID: mdl-37230620

ABSTRACT

Lightweight and highly compressible materials have received considerable attention in flexible pressure sensing devices. In this study, a series of porous woods (PWs) are produced by chemical removal of lignin and hemicellulose from natural wood by tuning treatment time from 0 to 15 h and extra oxidation through H2O2. The prepared PWs with apparent densities varying from 95.9 to 46.16 mg/cm3 tend to form a wave-shaped interwoven structure with improved compressibility (up to 91.89 % strain under 100 kPa). The sensor assembled from PW with treatment time of 12 h (PW-12) exhibits the optimal piezoresistive-piezoelectric coupling sensing properties. For the piezoresistive properties, it has high stress sensitivity of 15.14 kPa-1, covering a wide linear working pressure range of 0.06-100 kPa. For its piezoelectric potential, PW-12 shows a sensitivity of 0.443 V·kPa-1 with ultralow frequency detection as low as 0.0028 Hz, and good cyclability over 60,000 cycles under 0.41 Hz. The nature-derived all-wood pressure sensor shows obvious superiority in the flexibility for power supply requirement. More importantly, it presents fully decoupled signals without cross-talks in the dual-sensing functionality. Sensor like this is capable of monitoring various dynamic human motions, making it an extremely promising candidate for the next generation artificial intelligence products.

7.
Physiol Plant ; 175(1): e13842, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36543752

ABSTRACT

Potassium (K) application can alleviate cotton salt stress, but the regulatory mechanisms affecting cotton fiber elongation and ion homeostasis are still unclear. A two-year field experiment was conducted to explore the effects of K on the osmolyte contents (soluble sugar, K+ content, and malate) and related enzyme activities during the fiber elongation of two cotton cultivars with contrasting salt sensitivity (CCRI-79; salt tolerant cultivar, and Simian 3; salt-sensitive cultivar). Three K application treatments (0, 150, and 300 kg K2 O ha-1 ) were applied at three soil salinity levels (low salinity, EC = 1.73 ± 0.05 dS m-1 ; medium salinity, EC = 6.32 ± 0.10 dS m-1 ; high salinity, EC = 10.84 ± 0.24 dS m-1 ). K application improved fiber length and alleviated salt stress by increasing the maximum velocity of fiber elongation (Vmax ). The increase rate of K on fiber length decreased with elevating salt stress, and the increase rate of K on Vmax of CCRI-79 was greater than that of Simian3. K application can increase the enzyme activities (phosphoenolpyruvate carboxylase, PEPC, E.C. 4.1.1.31; pyrophosphatase, PPase, E.C. 3.6.1.1; and plasma membrane H+ -ATPase, PM H+ -ATPase, E.C. 3.6.3.14) as well as the content of osmolytes associated with the enzymes mentioned above. K increased the osmolyte contents under salt stress, and the increase in the K+ content of the fibers was much higher than that of soluble sugar and malate. The results of this study indicated K fertilizer application rates regulate the metabolism of osmolytes in cotton fiber development under salt stress, K+ is more critical to fiber elongation.


Subject(s)
Gossypium , Malates , Gossypium/physiology , Malates/metabolism , Potassium/metabolism , Salt Stress , Cotton Fiber , Homeostasis , Sugars/metabolism , Adenosine Triphosphatases/metabolism
8.
Bioresour Technol ; 363: 127977, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36122845

ABSTRACT

In organic acid hydrolysis for xylo-oligosaccharides (XOS) production, organic acids with low flash points and explosion limits can lead to explosion and fire risk. Herein, tartaric acid (TA) as an organic acid with high flash point and no explosion limit was used in the hydrolysis of corncob to produce XOS. Then, the TA-hydrolyzed corncob was used for ethanol production. In TA hydrolysis of corncob, a 56.4 % XOS yield was obtained from the hydrolysate with the conditions of 170 °C, 60 mM TA and 10 min. Meanwhile, 92.1 % TA was recovered from the hydrolysate by the addition of calcium hydroxide. After simultaneous saccharification and fermentation of TA-hydrolyzed corncob, an 82.4 % ethanol yield was obtained with a solid loading of 25 % (w/v, 250 g/L) by Saccharomyces cerevisiae H06. This research provided a relatively safe, simple, and efficient technology for producing XOS and ethanol from corncob.


Subject(s)
Ethanol , Zea mays , Calcium Hydroxide , Fermentation , Hydrolysis , Oligosaccharides , Saccharomyces cerevisiae , Tartrates
9.
Environ Sci Pollut Res Int ; 29(52): 78483-78498, 2022 Nov.
Article in English | MEDLINE | ID: mdl-35697982

ABSTRACT

As the health impacts of climate change take on a more serious form, this study for the first time investigates the effect of meteorological factors on the risk of death from respiratory diseases (RD) in Wuhu, a representative city along the Yangtze River in subtropical humid region. Daily meteorological element data and RD deaths in Wuhu City were collected from 2014 to 2020. Time series analysis was conducted using distributed lagged nonlinear model (DLNM) combined with generalized additive model (GAM), and stratified by age and gender. In 7 years, a total of 8016 RD death cases were collected in Wuhu, China. The results demonstrated that the maximum impacts of short-term exposure to exceedingly low temperatures mean (Tmean) were at lag 9, with the maximum relative risk (RR) of 1.044 (lag 1, 95% CI: 1.001, 1.098). The risk of exceedingly high Tmean reached its maximum at lag 0 (RR = 1.070, 95% CI: 1.018, 1.125). Low relative humidity (RH) was negatively associated with the risk of RD death, with the lowest RR values occurring at lag 12 (RR = 0.987, 95% CI: 0.975, 0.999). No significant correlation was found for diurnal temperature range (DTR). Stratified analysis showed that Tmean exposure remained statistically significant for male, female and elderly, while RH and DTR only seemed to increase the mortality risk in the young. In a word, short-term exposure to extreme temperatures may increase the RD mortality risk in the population, and young people needed to be aware that exposure to exceedingly high RH and DTR also increased the risk.


Subject(s)
Meteorological Concepts , Rivers , Male , Female , Humans , Adolescent , Aged , Humidity , China/epidemiology , Hot Temperature , Temperature
10.
Bioresour Technol ; 355: 127300, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35562025

ABSTRACT

This study presents p-toluenesulfonic acid (p-TsOH) pretreatment combined with subsequent hydrogen-peroxide pretreatment for the fractionation of all lignocellulosic components from walnut shells (WNS). The main focus of this study is the production of fermentable sugars. During p-TsOH pretreatment (55% p-TsOH, 1:10 solid-to-liquid ratio, 90 °C, 120 min), 50.2% of lignin and 88.3% of xylan were dissolved. Subsequently, the p-TsOH pretreated WNS without washing (to reduce water consumption) was further pretreated with 40% (v/v) H2O2 and 74.6% of lignin was removed at 60 °C for 120 min. Compared with the glucose yield of 10.2% from p-TsOH pretreated WNS, the glucose yield from the p-TsOH/H2O2 pretreated WNS could be significantly improved to 94.4%. Structural characterization analysis showed increases in porosity, biomass disruption, and cellulose crystallinity during p-TsOH/H2O2 pretreatment. Mass balance demonstrated that 1000 g of WNS produced 295.1 g of fermentable sugars (263.6 g glucose and 31.5 g xylose).


Subject(s)
Juglans , Lignin , Benzenesulfonates , Biomass , Glucose , Hydrogen Peroxide , Hydrolysis , Lignin/chemistry , Sugars
11.
Bioprocess Biosyst Eng ; 45(6): 1011-1018, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35312864

ABSTRACT

This study proposed a recyclable p-toluenesulfonic acid (p-TsOH) fractionation process for co-producing lignin nanoparticles (LNPs) and fermentable sugars from lignocellulosic biorefinery biowaste (enzymatic hydrolysis residue (EHR)). The prepared LNPs were used to detoxify the inhibitors in the xylose-rich prehydrolyzate for improving ethanol production. Results showed that the EHR was fractionated into a cellulose-rich water-insoluble solid (WIS) fraction and a lignin-rich spent liquor (SL) fraction. Cellulase hydrolysis of WIS produced 97.7% of glucose yield, while the LNPs of an average particle size of 98.0 nm with 76.3 % yield (based on the untreated EHR) were obtained from the diluted SL. LNPs demonstrated higher detoxification ability than EHR at the same dosage. Moreover, the fermentability of the detoxified xylose-rich prehydrolyzate was significantly improved. The sugar utilization ratio was 94.8%, and the ethanol yield reached its peak value of 85.4% after 36 h of fermenting the detoxified xylose-rich prehydrolyzate.


Subject(s)
Lignin , Nanoparticles , Ethanol , Fermentation , Hydrolysis , Lignin/chemistry , Xylose
12.
Pain Ther ; 11(2): 613-626, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35312948

ABSTRACT

INTRODUCTION: The analgesic effect and safety of transversus abdominis plane block (TAPB) is still controversial in various abdominal procedures. Quadratus lumborum block (QLB) has been considered to provide a widespread and long-lasting analgesic effect in gynecological surgeries. However, the analgesic effects of these two techniques in patients with extreme obesity undergoing laparoscopic sleeve gastrectomy (LSG) are still unknown. METHODS: A total of 225 patients with obesity were randomly assigned to group TAPB (n = 76, 30 ml 0.33% ropivacaine with dexmedetomidine 1 µg kg-1), group QLB (n = 76, 30 ml 0.33% ropivacaine with dexmedetomidine 1 µg kg-1), or general anesthesia alone (GA, n = 73, 30 ml 0.9% saline). During the 48-h postoperative period, patients received continuous intravenous patient-controlled analgesia (PCA) containing sufentanil 2 µg kg-1, dexmedetomidine 2 µg kg-1, and granisetron 3 mg. The scores of visual analogue scale (VAS) in surgical incision and viscera, considering as the primary outcomes, were continuously recorded at postoperative 0, 0.5, 1, 2, 6, 12, 24, 48 h and discharge. RESULTS: Comparing with patients in the GA group, VAS scores of incision and viscera were consistently reduced during the initial 6-12 h after LSG in TAPB and QLB groups, and they received less propofol and remifentanil (P < 0.001) as well. In the QLB group, patients had longer duration for the first rescue analgesia, and fewer requirements of the rescue analgesia within 24 h than the GA group (P < 0.05). In addition, there were fewer PCA requirements in QLB group than GA and TAPB groups (P < 0.05). CONCLUSIONS: Ultrasound-guided transversus abdominis plane block and quadratus lumborum block could provide comparable analgesic effects for a laparoscopic sleeve gastrectomy in obese patients. TRIAL REGISTRATION: Chinese Clinical Trial Registry; ChiCTR1800019236.

13.
J Biomech Eng ; 144(8)2022 08 01.
Article in English | MEDLINE | ID: mdl-35079785

ABSTRACT

Finite element (FE) modeling has been used as a research tool for investigating underlying ligaments biomechanics and orthopedic applications. However, FE models of the ligament in the foot have been developed with various configurations, mainly due to their complex three-dimensional geometry, material properties, and boundary conditions. Therefore, the purpose of this review was to summarize the current state of finite element modeling approaches that have been used in the field of ligament biomechanics, to discuss their applicability to foot ligament modeling in a practical setting, and also to acknowledge current limitations and challenges. A comprehensive literature search was performed. Each article was analyzed in terms of the methods used for: (a) ligament geometry, (b) material property, (c) boundary and loading condition related to its application, and (d) model verification and validation. Of the reviewed studies, 79.8% of the studies used simplified representations of ligament geometry, the nonlinear mechanical behavior of ligaments was taken into account in only 19.2% of the studies, 33.6% of included studies did not include any kind of validation of the FE model. Further refinement in the functional modeling of ligaments, the microstructure level characteristics, nonlinearity, and time-dependent response, may be warranted to ensure the predictive ability of the models.


Subject(s)
Ligaments , Models, Biological , Biomechanical Phenomena , Finite Element Analysis , Foot , Ligaments/physiology , Ligaments, Articular , Stress, Mechanical
14.
Bioresour Technol ; 347: 126683, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34999193

ABSTRACT

The preparation of xylooligosaccharides (XOS) from lignocelluloses by organic acid hydrolysis has the advantages of high efficiency and simplicity, but reducing the production of by-products, especially xylose, is a prerequisite for commercial preparation of XOS using organic acid. In this work, to reduce the production of by-products, the acetic acid/sodium acetate conjugate system (AC/SA) was used to prepare XOS from poplar. Under the optimal conditions (0.15 M AC/SA, molar ratio of 3.0, 175 °C, 60 min), the maximum XOS yield was 33.6% with a low xylose/XOS ratio of 0.19. Xylanase hydrolysis effectively converted XOS with DP above 6 in the AC/SA hydrolysate to X2-X6 with little xylose produced. The XOS yield increased to 42.1%, with a xylose/XOS ratio was only 0.17. This work shows that AC/SA in combination with xylanase hydrolysis of poplar successfully achieved high XOS yield with low by-products yields without the extraction of xylan from the substrate.


Subject(s)
Acetic Acid , Glucuronates , Endo-1,4-beta Xylanases , Hydrolysis , Oligosaccharides , Sodium Acetate , Xylans
15.
Knee Surg Sports Traumatol Arthrosc ; 30(1): 116-123, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34499210

ABSTRACT

PURPOSE: An understanding of the behavior of a new ACL graft in the femoral tunnel during knee motion and external loading can provide information pertinent to graft healing, tunnel enlargement, and graft failure. The purpose of the study was to measure the percentage of the tunnel filled by the graft and determine the amount and location of the graft-tunnel contact with knee motion and under external knee loads. METHODS: Single bundle anatomical ACL reconstruction was performed on six cadaveric knees. Specimens were positioned with a robotic testing system under: (1) passive flexion-extension, (2) 89-N anterior and posterior tibial loads, (3) 5-N m internal and external torques, and (4) 7-N m valgus moment. The knees were then dissected, repositioned by the robot and the geometry of the femoral tunnel and graft were digitized by laser scanning. The percentage of tunnel filled and the contact region between graft and tunnel at the femoral tunnel aperture were calculated. RESULTS: The graft occupies approximately 70% of the femoral tunnel aperture and anterior tibial loading tended to reduce this value. The graft contacted about 60% of the tunnel circumference and the location of the graft-tunnel contact changed significantly with knee flexion. CONCLUSION: This study found that the graft tends to rotate around the tunnel circumference during knee flexion-extension and contract under knee loading. The "windshield-wiper" and "bungee cord" effect may contribute to femoral tunnel enlargement, affect graft healing, and lead to graft failure. There can be a considerable motion of the graft in the tunnel after surgery and appropriate rehabilitation time should be allowed for graft-tunnel healing to occur. To reduce graft motion, consideration should be given to interference screw fixation or a graft with bone blocks, which may allow an earlier return to activity.


Subject(s)
Anterior Cruciate Ligament , Femur , Biomechanical Phenomena , Cadaver , Femur/surgery , Humans , Knee Joint/surgery , Range of Motion, Articular , Tibia
16.
Zhongguo Zhong Yao Za Zhi ; 46(19): 4875-4880, 2021 Oct.
Article in Chinese | MEDLINE | ID: mdl-34738380

ABSTRACT

Due to the diverse sources and unique structures, the chemical components of Chinese medicinal materials are easy to self-assemble to form nanoparticles. The formation of self-assembled nanoparticles(SAN) can not only affect the absorption and distribution of the effective ingredients in Chinese medicinal materials but also may improve the biological activity of the effective ingredients or their simple mixtures, which is of great significance for revealing the compatibility mechanism of Chinese medicine prescription, developing new Chinese medicine products, and producing new nanomaterials. This paper reviews the formation, isolation, characterization, and application of SAN of Chinese medicines, and discusses the problems and development trends of the relevant research, which can provide reference for the further study and promote the innovation and application of such SAN.


Subject(s)
Drugs, Chinese Herbal , Nanoparticles , Medicine, Chinese Traditional , Prescriptions
17.
Bioresour Technol ; 342: 125943, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34547710

ABSTRACT

Recently, xylo-oligosaccharides (XOS) production from lignocelluloses by organic acid catalysis has been widely reported. However, the effect of delignification of lignocelluloses on XOS production by organic acid catalysis was unclear, and lactic acid (LA) catalysis in XOS production from lignocelluloses has not been reported. In this work, the effect of delignification on XOS production from poplar by LA catalysis was investigated. Results demonstrated that hydrogen peroxide-acetic acid (HPAA) pretreatment removed 83.2% of lignin and retained 95.4% of xylan. After 2% LA catalysis (170 °C, 30 min), a high XOS yield of 42.7% was obtained from HPAA1-LA-pretreated poplar. Lignin removal from poplar was positively correlated with XOS yield. Glucose yield of HPAA1-LA-pretreated poplar by cellulase was 88.9%. Compared with LA-catalyzed poplar, the XOS and glucose production from HPAA1-LA-pretreated poplar by cellulase increased by 1.4-fold and 6.8-fold, respectively. This work presents a novel strategy for efficient producing XOS and monosaccharides from poplar.


Subject(s)
Lactic Acid , Populus , Catalysis , Hydrolysis , Oligosaccharides
18.
Bioresour Technol ; 340: 125624, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34364082

ABSTRACT

High solid loading saccharification is the premise of preparing high-concentration sugar which is beneficial to bioethanol production, but the limited sugar concentration and high enzyme dosage are two challenges. In this work, the glucan-rich acetic acid-hydrogen peroxide/acetic acid (AC-HPAC)-pretreated poplar (85.8%) were prepared for enzymatic hydrolysis at 10%-40% solid loading and the strategies for reducing cellulase dosage were explored. Results showed that the maximum glucose concentration reached to 250.8 g/L at 40% solid loading, which was the highest concentration in previous literatures. As the solid loading was 20%, the addition of Tween 80 saved 50% of cellulase and the recycling of unhydrolyzed residue (0.2 g/g DM) saved another 25% of cellulase, resulting in 152.2 g/L of glucose concentration with yield of 79.9%. This work showed potential of poplar to produce the high concentration glucose solution with low enzyme loading through the recycling of enzyme bound onto unhydrolyzed residue.


Subject(s)
Cellulase , Acetic Acid , Cellulose , Hydrolysis , Peroxides
19.
Biotechnol Biofuels ; 14(1): 151, 2021 Jul 02.
Article in English | MEDLINE | ID: mdl-34215309

ABSTRACT

BACKGROUND: Hydrogen peroxide-acetic acid (HPAA) is widely used in pretreatment of lignocellulose because it has a good capability in selective delignification. However, high concentration (more than 60%) of HPAA increases the cost of pretreatment and the risk of explosion. In this work, alkaline post-incubation was employed to decrease the HPAA loading and improve the saccharification of poplar. RESULTS: Pretreatment with 100% HPAA removed 91.0% lignin and retained 89.9% glucan in poplar. After poplar was pretreated by 100% HPAA at 60 °C for 2 h, the glucan conversion in enzymatic hydrolysis by cellulase increased to 90.1%. Alkaline incubation reduced the total lignin, surface lignin, and acetyl group of HPAA-pretreated poplar. More than 92% acetyl groups of HPAA-pretreated poplar were removed by alkaline incubation with 1.0% NaOH at 50 °C for 1 h. After incubation of 60% HPAA-pretreated poplar with 1.0% NaOH, the glucan conversion enhanced to 95.0%. About 40% HPAA loading in pretreatment was reduced by alkaline incubation without the decrease of glucose yield. CONCLUSIONS: Alkaline post-incubation had strong ability on the deacetylation and delignification of HPAA-pretreated poplar, exhibiting a strong promotion on the enzymatic hydrolysis yield. This report represented alkaline incubation reduced the HPAA loading, improved pretreatment safety, exhibiting excellent potential application in saccharification of poplar.

20.
Zhongguo Zhong Yao Za Zhi ; 46(9): 2190-2196, 2021 May.
Article in Chinese | MEDLINE | ID: mdl-34047120

ABSTRACT

To study the effect of self-assembled nanoparticles from Shaoyao Gancao Decoction(SGD-SAN) on the encapsulation, in vitro release and intestinal absorption of the main components of Baishao. Particle size analysis and morphological observation were used to verify the formation of SGD-SAN in the decoction. The entrapment efficiency(EE) of SGD-SAN on the main components of Baishao was determined by ultrafiltration centrifugation. The dialysis bag method was used to study the in vitro release of the main components of Baishao with pH 6.8 phosphate buffer solution as the release media. Single-pass intestinal perfusion study was performed to investigate the effect of SGD-SAN on the absorption of the main components of Baishao. The results showed that there were nanoparticles in the SGD, and the particle sizes and PDI of SGD-SAN were about 200 nm and 0.38, respectively. SGD-SAN was irregularly spherical under transmission electron microscope(TEM). The EEs of albiflorin, paeoniflorin and benzoylpaeoniflorin in SGD-SAN were 33.78%±1.03%,33.61%±0.90%,88.53%±0.58%, respectively. The release characteristics of albiflorin, paeoniflorin and benzoylpaeoniflorin from SGD-SAN showed a slow-release effect on pH 6.8 phosphate buffer solution media. SGD-SAN could significantly enhance the absorption of albiflorin, paeoniflorin and benzoylpaeoniflorin in the ileum. The results of this study indicated that SAN could be formed during the mixed decoction of Baishao and Gancao, and SGD-SAN could encapsulate the components of Baishao, with a certain slow-release effect, and the formation of SAN facilitated the absorption of drugs in the ileum.


Subject(s)
Drugs, Chinese Herbal , Nanoparticles , Glycyrrhiza , Intestinal Absorption , Intestines
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