Effect of Plasticization on Stretching Stability of Poly(Vinyl Alcohol) Films: A Case Study Using Glycerol and Water.

Adding small molecular plasticizers is the most common route to tailor the stretchability of poly(vinyl alcohol) (PVA). However, how the plasticization along with the nature of the plasticizer governs the structural homogeneity during stretching remains an open question to answer. Herein, two representative plasticizers, glycerol (GLY) and water, are chosen to endow the PVA films with ductility. It is found that large strain cavitations cause obvious stress whitening in the PVA/H2 O films; on the contrary, most of the PVA/GLY films maintain transparent undergoing tensile deformation. Through a combination of experimental inspections and molecular dynamic simulation, it is revealed that partial water molecules that behave as free water will aggregate into microdomains, which serve as mechanical defects responsible for yielding voids. Whereas, the GLY plasticizer homogeneously disperses at a molecular level and interacts with PVA chains through strong hydrogen bonds. More interestingly, it is illustrated that the dispersion and bound states of plasticizers are closely related to the mechanical character of the plasticized PVA films. These findings offer new insight into the working mechanism of plasticization on the structural stability during stretching, and guide the design of PVA/plasticizer system to obtain excellent comprehensive mechanics.

A study of congenital generalized lipodystrophy (CGL) caused by BSCL2 gene mutation.

Congenital generalized lipodystrophy (CGL) is an extremely rare genetic disease mainly characterized by absence of whole-body adipose tissue and metabolic dysfunctions such as insulin resistance, diabetes mellitus, hypertriglyceridemia, hepatic steatosis, and acanthosis nigricans. In this study, we reported a novel case of a young woman patient with CGL. The patient came to the hospital for early-onset lipodystrophy and diabetes. She was 19-year-old with a height of 160 cm, a weight of 46 kg, BMI of 17.9 kg/m2, and a serum leptin level of 0.14 µg/L. Genomic DNA was extracted from blood samples of the patient and her family members, including her mother, father and brother. Genetic analysis revealed compound heterozygous mutations of the BSCL2 gene (c.560A>G and c.565G>T) in the patient. Her father carried a heterozygous mutation (c.565G>T), and her mother carried a heterozygous mutation (c.560A>G) in the BSCL2 gene. The mutant p.Y187C plasmid was transfected into HEK293T cells. The protein expression of SEIPIN and its interaction with glycerol-3-phosphate acyltransferase (GPAT3) were observed to be reduced. In addition, based on primary cultured skin fibroblasts from the patient, SEIPIN protein was decreased, and lipid droplets were much smaller when fatty acid was stimulated compared with those observed from healthy subject controls. However, histone deacetylase inhibitors (HDACis) was found capable of rescuing SEIPIN protein in fibroblasts of the patient. In addition, we further summarized and discussed gene mutations of BSCL2 reported in the current literature. Collectively, these findings have expanded the clinical phenotype and pathogenic gene spectrum of CGL, which might help clinicians to achieve better management of lipodystrophy.

Establishment and operation of glucose clamp technique in mice.

Glucose metabolism plays a central role in energy supply and metabolism regulation in various tissues and organs. Besides, insulin is the sole hormone lowering blood glucose in the body, and islet function and insulin sensitivity are the key steps modulating glucose metabolism. Since the development of glucose clamp technology, it has been recognized as the gold standard for evaluating insulin metabolism. The main categories include hyperinsulinemia-euglycemia clamp, hyperglycemia clamp, and hyperinsulinemia-hypoglycemia clamp. These can be done on either anesthetized mice or conscious and unrestricted mice. This protocol focuses on the establishment and operation of the mouse glucose clamp technique, including preparation of instrument consumables, surgical operations, clamping procedures, and precautions, serving as reference and guidance.

Diagnosis and genetic analysis of a case with glycogen storage disease type V caused by compound heterozygous mutations in the PYGM gene.

Glycogen storage disease type V is an autosomal recessive genetic disorder caused by muscle glycogen phosphorylase (PYGM) deficiency, which is characterized by exercise intolerance, second wind phenomena and high level of serum creatine kinase. In this study, we reported a Chinese young man with glycogen storage disease type V, with lower extremity weakness after exercise, increased creatine kinase, and slight fat infiltration in the posterior group of thigh muscle by magnetic resonance imaging (MRI). The proband had complex heterozygous PYGM disease-causing mutations, including c.308T>C (p.L103P) variant transmitted from the mother and c.260_261delCT (p.S87Ffs*23) from the father, of which the former was a novel PYGM mutation. This study enriched the PYGM pathogenic gene mutation spectrum, contributed to improve clinicians' understanding of glycogen storage disease type V and provided a reference for further genetic study of the disease.

Pursuing Phase Transitions of a Concentrated Polymer Solution by In Situ Fluorescence Measurements Based On Aggregation-Induced Emission.

Concentration-dependent phase transitions in concentrated solutions have remained speculation due to the serious impediment of macromolecule dynamics by intensive topological entanglement or intermolecular interaction as well as the absence of powerful tool for detecting changes in chain or segment movement. Herein, taking a general polymer, namely, poly(vinyl alcohol) (PVA), as an example, a water-soluble fluorescent molecule with aggregation-induced emission (AIE) is introduced into the PVA solutions as a chain dynamics indicator to investigate phase transitions at high concentrations through in situ monitoring of the solvent evaporation process. Two turning points of fluorescent intensity are observed for the first time at mean concentrations of ∼25% and ∼45%, corresponding to the gelation and amorphous-to-crystalline transitions, respectively. Our work offers a fundamental insight into the physical nature of concentrate-dependent nonequilibrium transitions and develops a reliable and sensitive approach based on the AIE phenomenon for following high-concentration-triggered property changes of a polymer solution.

p38MAPK silencing attenuates scar proliferation after cleft palate repair surgery in rats via MRTF-A/SRF pathway.

Scarring is the primary factor of maxilla growth restriction among people who have undergone cleft palate repair surgery. p38 mitogen-activated protein kinase (p38MAPK) promotes fibrosis in a variety of organs. However, its role in post-surgery scarring on the hard palate has not been fully understood. This study is designed to investigate the role of p38MAPK in scar formation and maxilla growth of rats. We removed the mucosa on the hard palate of rats and applied the p38MAPK silencing adenovirus vector on it two weeks after surgery. Then the scarring tissue and maxilla growth were evaluated by histological and morphological examination. The effect of p38MAPK silencing on scarring-related genes in fibroblasts was also studied. We found that local injection of Ad-p38MAPK-1 in vivo effectively reduces the expression of p38MAPK and scarring-related proteins and weakens the impact of scarring on the width of the hard palate. Mechanistically, p38MAPK silencing inhibits the expression of α-smooth muscle actin (α-SMA) via mediating the production and nuclear localization of myocardin-related transcription factor A (MRTF-A) in fibroblasts. These results reveal a molecular pathway of scar formation involving p38MAPK/MRTF-A stimulation and support targeting p38MAPK as a potentially effective treatment for post-surgery scarring on the hard palate.

Hydrogen-bond-dominated mechanical stretchability in PVA films: from phenomenological to numerical insights.

Hydrogen bonds (H-bonds) in poly(vinyl alcohol) (PVA) play a crucial role in macroscopic mechanical properties, particularly for stretchability. However, there is still some ambiguity about the quantitative dependence of H-bond interactions on the mechanical performance, mainly attributed to the difficulty in the discrimination of various H-bond types. Herein, small molecular chemicals as plasticizers were incorporated into the PVA matrix to tailor the H-bonding interactions. By altering the PVA molecular weight, plasticizer type and loading, both the stretchability and H-bond content were regulated on a large scale. By a combination of DMA, IR spectroscopy, MD simulation and solid-state 13C-NMR, every sort of H-bond in PVA was assigned, and their relative fractions were ascertained quantitatively. After correlating the elongation ratio with the relative fraction of the different types of H-bonding interaction, it was found that all the pairs of elongation vs. intermolecular H-bond content derived from different series of PVA/plasticizer films could be plotted into a master curve and exhibited good linearity, indicating that intermolecular H-bonds dominate the mechanical stretchability in PVA films. Our efforts contribute towards an in-depth understanding of performance optimization induced by H-bond manipulation from empirical, phenomenological aspects to intrinsic, numerical insights.

Virtual Surgical Planning and Three-Dimensional Printing to Aid the Anatomical Reduction of an Old Malunited Fracture of the Mandible.

ABSTRACT: Mandible fracture is a common injury in maxillofacial surgery. It causes not only maxillofacial dysfunction but also facial deformities. Malunited fractures of the mandible have been a vast challenge in clinical treatment due to the misalignment of the broken ends and the occurrence of occlusal disorders. This case report describes using virtual surgical planning and three-dimensional printing to treat a patient with malunited fracture of the mandible. Failing to perform mandibular surgery due to severe brain trauma after the car accident, the patient got malunited healing of mandible. The authors applied virtual surgical planning to perform preoperative analysis and surgical design on this patient, three-dimensional printing to fabricate occlusal plate, and models of the preoperative and postoperative mandible to guide the operation. Finally, the authors achieved the reduction and reconstruction of the mandible with satisfactory clinical results.

Treatment of oral lichen planus by surgical excision and acellular dermal matrix grafting: Eleven case reports and review of literature.

BACKGROUND: Oral lichen planus (OLP) is a chronic inflammatory disorder, and it can affect normal oral function. The conventional treatments for OLP are not always effective, and relapse easily occurs. Therefore, treatment of OLP is difficult and challenging. In this study, we evaluated over a long period the clinical efficacy of surgical excision and acellular dermal matrix (ADM) grafting in patients with refractory OLP. CASE SUMMARY: Eleven patients with refractory OLP underwent a standardized protocol of surgical excision and ADM grafting. The condition of the area of the grafted wound, the intraoperative maximum mouth opening, pain, and clinical healing were assessed at postoperative follow-up visits. All patients had a flat surgical area with similar mucosal tissue coverage and local scar formation. Patients had no irritation and pain in their mucous membranes when eating acidic and spicy food. All patients' mouth openings returned to normal within 2-6 mo after surgery. During follow-up, none of the patients had recurrence of OLP after surgery. The longest follow-up was 11 yr and the shortest was 6 mo, and none of the patients relapsed during follow-up. CONCLUSION: Surgical excision and ADM grafting could be an effective method to treat refractory OLP.

Negative pressure drainage-assisted irrigation for maxillofacial space infection.

OBJECTIVE: In this study, the clinical effect of negative pressure drainage-assisted irrigation (NPDI) technique was evaluated in treating maxillofacial space infection (MSI) by comparing with traditional technique. METHOD: A prospective study was conducted in 58 patients with MSI. The patients were randomly divided into two groups based on different treatment techniques. Thirty patients receiving NPDI were included in NPDI group, and 28 patients receiving traditional technique were included in traditional group. Case data (gender, age, etiology, concurrent illness, diabetes, involved spaces, preoperative white cell count, airway control method) and clinical effect (postoperative hospital stay, total cost of admission) for the two groups were analyzed. RESULTS: Patients in both groups were cured clinically. There were no significant differences in gender, age, etiology, concurrent illness, diabetes, involved spaces, preoperative white cell count, and airway control method in NPDI group and traditional group (p > .05). The postoperative hospital stay and the total cost of admission in the NPDI group were significantly lower than the traditional group (p < .001). CONCLUSION: Negative pressure drainage-assisted irrigation used in the treatment of MSI can shorten the postoperative hospital stay, reduce the total cost of admission, and show favorably clinical effect. It is a clinically recommended method for MSI.

[Influence of transplantation and some clinical factors on prognosis of patients with diffuse large B-cell lymphoma].

This study was aimed to analyze the survival status of patients with diffuse large B-cell lymphoma (DLBCL) and to investigate the influence of autologous hematopoietic stem cell transplantation (auto-HSCT), different pathological types, International Prognosis Idex (IPI) on prognosis. One hundred and sixteen cases of DLBCL were analyzed retrospectively. The treatment efficacy of R-CHOP alone and R-CHOP combined with auto-HSCT as well as the influence of different immunopathologic types, IPI, hypersensitive C-reactive protein (HSCRP), α-hydroxybutyric acid deaminase (HBDH) on the prognosis of DLBCL patients including overall survival (OS) rate, progression-free survival (PFS) rate were analyzed. The results indicated that the 5-year OS for all patients was 72.4%. in which 30 patients with Ann Arbor staging III-IV received auto-HSCT plus R-CHOP. The prognosis of the 30 patients was better than that of 86 cases received R-CHOP chemotherapy alone (5-year OS was 82.5% vs 69.0%, 5-year PFS was 77.1% vs 68.3%) (P < 0.05). The prognosis of patients in germinal center B-cell-like group (GCB group) was better than that of patients in activated B-cell-like group (ABC group). Some clinical features were associated with poor prognosis including OS and PFS, such as age, B symptoms, IPI scores, the level of LDH, HSCRP and HBDH (P < 0.05) in which the level of LDH, age ≥ 60 years and B symptoms were independent prognostic factors in DLBCL patients (P < 0.05). It is concluded that auto-HSCT combined with R-CHOP can improve the long-term survival of DLBCL patients. The prognosis of patients in GCB group is better than that of patients in the ABC group. The clinical features such as age, B symptoms, IPI scores and LDH are associated with prognosis.

Highly sensitive fluorescent immunoassay of human immunoglobulin G based on PbS nanoparticles and DNAzyme.

This paper reports a highly sensitive fluorescent immunoassay for the detection of human immunoglobulin G based on PbS nanoparticles and DNAzyme. A sandwich immunoassay format was performed on a microtiter plate. Goat anti-human IgG was coated onto the polystyrene microtiter plate. The human IgG analyte was first captured by the goat anti-human IgG, and then sandwiched by a goat anti-human IgG antibody labeled with PbS nanoparticles. After being dissolved with HNO3, the released Pb(2+) made the substrate chain of the DNAzyme labeled with the fluorophore dissociate from the enzyme strand of the DNAzyme labeled with the quencher, which resulted in fluorescence recovery. Then, the human IgG could be detected indirectly from the fluorescent signals. Under the optimized conditions, the linear range of the developed immunosensor was from 1 ng mL(-1) to 10 µg mL(-1) with a detection limit of 0.8 ng mL(-1). This immunosensor could be used to detect the amount of human IgG in human serum samples.