Recycling of waste crab shells into reinforced poly (lactic acid) biocomposites for 3D printing.

To promote natural waste resource utilization, a novel biocomposite, composed of waste crab shells and poly (lactic acid) matrix, was developed by combining chemical treatment and 3D printing. A crab shell powder (ISCSP) with an abundant porous structure and a high specific surface area was obtained by treatment with hydrochloric acid and sodium hydroxide. Importantly, under the optimal printing parameters determined by the finite element analysis, test samples, and porous bones were successfully printed using CSP/PLA composites by a commercial fused deposition modeling (FDM) 3D printer. The morphology, mechanical and thermal properties, antibacterial properties, and biocompatibility of the CSP/PLA composites were then assessed. Our results revealed that the tensile strength and flexural strength of the ISCSP/PLA composites reached 58.71 and 90.11 MPa, which were 28.6 % and 28.8 % higher than that of pure PLA, respectively. The glass transition and melting temperatures of the composites remained similar to those of pure PLA. Interestingly, the addition of CSP increased PLA crystallinity, which could be attributed to the nucleation effect of CSP in the system. The antibacterial activity of the PLA-1.5ESCSP composite samples against Escherichia coli (E. coli) was greater than 99 %. More importantly, the live/dead assay showed that the CSP/PLA composites possessed excellent biocompatibility. Therefore, the developed CSP/PLA biocomposites are potential feedstocks for 3D printing in bone tissue engineering and may be used as graft substitutes in reparative and reconstructive surgery. They are especially beneficial due to their superior mechanical and thermal properties, excellent antibacterial activities, and significant biocompatibility.

Micrometer Copper-Zinc Alloy Particles-Reinforced Wood Plastic Composites with High Gloss and Antibacterial Properties for 3D Printing.

In this work, micrometer copper-zinc alloy particles-reinforced particleboard wood flour/poly (lactic acid) (mCu-Zn/PWF/PLA) wood plastic composites with high gloss and antibacterial properties for 3D printing were prepared by a melt blending process. The structure and properties of the composites with different contents of mCu-Zn were analyzed by means of mechanical testing, dynamic mechanical analysis, thermogravimetric analysis, differential scanning calorimetry, X-ray diffraction, scanning electron microscopy, and antibacterial testing. The results showed that the mechanical properties, thermal stability, and antibacterial performance of the composites were significantly improved, as mCu-Zn was added into the wood plastic composites. When adding 2 wt.% mCu-Zn, the flexural strength of mCu-Zn/PWF/PLA composites (with 5 wt.% of particleboard wood flour) (PWF) increased by 47.1% compared with pure poly (lactic acid) (PLA), and 18.9% compared with PWF/PLA wood plastic composites. The surface gloss was increased by 1142.6% compared with PWF/PLA wood plastic composites. Furthermore, the inhibition rates of mCu-Zn/PWF/PLA composites against Escherichia coli reached 90.43%. Therefore, this novel high gloss and antibacterial wood plastic composites for fused deposition modeling (FDM) 3D printing have potential applications in personalized and classic furniture, art, toys, etc.

Multipole gap solitons in fractional Schrödinger equation with parity-time-symmetric optical lattices.

We investigate the existence and stability of in-phase three-pole and four-pole gap solitons in the fractional Schrödinger equation supported by one-dimensional parity-time-symmetric periodic potentials (optical lattices) with defocusing Kerr nonlinearity. These solitons exist in the first finite gap and are stable in the moderate power region. When the Lévy index decreases, the stable regions of these in-phase multipole gap solitons shrink. Below a Lévy index threshold, the effective multipole soliton widths decrease as the Lévy index increases. Above the threshold, these solitons become less localized as the Lévy index increases. The Lévy index cannot change the phase transition point of the PT-symmetric optical lattices. We also study transverse power flow in these multipole gap solitons.

Novel chitosan hydrogels reinforced by silver nanoparticles with ultrahigh mechanical and high antibacterial properties for accelerating wound healing.

Poor mechanical properties of chitosan hydrogels limit their applications as the wound dressing. To overcome this drawback, we abandoned the traditional glacial acetic acid method but adopted a LiOH/urea solvent system to synthesize chitosan hydrogel. Then reductive Ag nanoparticles were integrated into the chitosan hydrogel networks, aiming at reinforcing the mechanical properties and improving the antibacterial properties of chitosan hydrogel. The synthesized hydrogels were subsequently characterized using the FTIR, XRD, SEM, and TEM. In addition, swelling characteristics, mechanical properties, antibacterial abilities as well as wound healing efficacy on Sprague-Dawley rats were evaluated. The results showed that the novel hydrogel exhibited porous three-dimensional network and ultrahigh mechanical properties due to the inter-molecular and intra-molecular interactions. The compressive strength was 15.95 ±â€¯1.95 MPa, >100 times stronger than that of the control group. Meanwhile, the hydrogels still remained structural integrity even if the strain exceeded 90%. Furthermore, compared with the controls, the hydrogels exhibited more excellent antibacterial performance and significantly (p < 0.05) increased the rate of the re-epithelialization and collagen deposition, effectively accelerating the wound healing. Therefore, the synthesized hydrogel with ultrahigh mechanical properties will be found potential applications in the fields of biomedicine.

Secondary mania associated with enterococcal meningitis in an elderly patient.

Primary mania is associated with bipolar disorder, whereas secondary mania may result from many etiologies, including metabolic, pharmacological and neurological causes. Strong evidence has shown that, in older adults, new onset mania is more likely associated with an underlying cause, suggesting that late-onset mania is often secondary [Bipolar Disord. 2004;6(5):343-67]. Cryptococcal meningitis has been reported to induce secondary mania [Gen Hosp Psychiatry. 2005;27(4):301-3]. Here, we present a 75-year-old female patient who developed mania as a symptom of enterococcal meningitis. To our knowledge, this is the first report describing secondary mania in a case of enterococcal meningitis.

Multiple intracerebral hemorrhages in an elderly patient after adding quetiapine to a stable warfarin regimen.

The efficacy of antipsychotics in patients with dementia exhibiting psychiatric symptoms has been overshadowed by safety concerns in recent years. Evidence suggests that the long-term use of antipsychotics in older adults is associated with a greater risk of cerebrovascular adverse events than accrues with short-term use (less than 30 days) [J Clin Psychiatry. 2010;71(6):689-98]. Here, we present an elderly male patient with dementia who developed multiple intracerebral hemorrhages (ICHs) 3 days after the addition of quetiapine to his stable warfarin regimen. To our knowledge, this is the second case of possible interaction between quetiapine and warfarin. We suggest mechanisms that may account for the patient's clinical presentation and highlight that combining treatment with quetiapine and warfarin may cause serious complications in patients with risk factors for ICH.

Delayed-onset diurnal bruxism, psychic akinesia and depression after carbon monoxide poisoning: a case report.

Diagnosing the delayed neuropsychological sequelae of carbon monoxide (CO) poisoning is a clinical challenge because of its varied presentations. Pallidal lesions, the most common site of involvement in CO poisoning [Clin Radiol. 2000;55(4):273-80] can cause psychic akinesia [Mov Disord. 2001;16(5):810-4; J Neurol Neurosurg Psychiatry 1984;47(4):377-85]. We present a patient with diurnal bruxism, psychic akinesia and depression that were delayed manifestations of CO poisoning.

Comparison of the efficacy and impact on cognition of glycopyrrolate and biperiden for clozapine-induced sialorrhea in schizophrenic patients: a randomized, double-blind, crossover study.

BACKGROUND: Clozapine-induced sialorrhea (CIS) is a subjective distressing adverse effect and occurs in 31%-57% of schizophrenic patients receiving clozapine therapy. Current pharmacotherapy on CIS has focused on anticholinergic agents, even though they may impair cognitive function. Previous case reports have suggested the benefit of glycopyrrolate or biperiden in treating this condition, but no randomized controlled trial has provided evidence. The objective of our study was to evaluate the efficacy and impact on cognition of glycopyrrolate and biperiden treatments for schizophrenic patients suffering from CIS. METHODS: Patients who satisfied the inclusion criteria entered a 12-week, randomized, double-blind, crossover, fixed-dose trial. The study consisted of two 4-week crossover phases, which were separated by a 4-week washout period. Sialorrhea and global cognitive function were assessed by using a Drooling Rating Scale (DRS) and the Mini Mental State Examination (MMSE), respectively. RESULTS: Throughout the study, patients treated with glycopyrrolate or biperiden had significantly reduced DRS scores. Moreover, the DRS scores were significantly lower with glycopyrrolate treatment than with biperiden. In other respects, there were no significant differences in MMSE scores in patients treated with glycopyrrolate. However, we found a significant reduction in MMSE scores in patients treated with biperiden. CONCLUSION: We provide evidence, for the first time, of the efficacy of glycopyrrolate and biperiden in the treatment of CIS. Furthermore, glycopyrrolate displays less impact on cognitive function. Consequently, glycopyrrolate can become a valid option for treating CIS. Observations from our study serve as a springboard for additional large-scale prospective trials.

Arsenic-induced Mre11 phosphorylation is cell cycle-dependent and defective in NBS cells.

Cancer-prone diseases ataxia-telangiectasia (AT), Nijmegen breakage syndrome (NBS) and ataxia-telangiectasia-like disorder (ATLD) are defective in the repair of DNA double-stranded break (DSB). On the other hand, arsenic (As) has been reported to cause DSB and to be involved in the occurrence of skin, lung and bladder cancers. To dissect the repair mechanism of As-induced DSB, wild type, AT and NBS cells were treated with sodium arsenite to study the complex formation and post-translational modification of Rad50/NBS1/Mre11 repair proteins. Our results showed that Mre11 went through cell cycle-dependent phosphorylation upon sodium arsenite treatment and this post-translational modification required NBS1 but not ATM. Defective As-induced Mre11 phosphorylation was rescued by reconstitution with full length NBS1 in NBS cells. Although As-induced Mre11 phosphorylation was not required for Rad50/NBS1/Mre11 complex formation, it might be required for the formation of Rad50/NBS1/Mre11 nuclear foci upon DNA damage.