Ultrauniform, strong, and ductile 3D-printed titanium alloy through bifunctional alloy design.

Coarse columnar grains and heterogeneously distributed phases commonly form in metallic alloys produced by three-dimensional (3D) printing and are often considered undesirable because they can impart nonuniform and inferior mechanical properties. We demonstrate a design strategy to unlock consistent and enhanced properties directly from 3D printing. Using Ti-5Al-5Mo-5V-3Cr as a model alloy, we show that adding molybdenum (Mo) nanoparticles promotes grain refinement during solidification and suppresses the formation of phase heterogeneities during solid-state thermal cycling. The microstructural change because of the bifunctional additive results in uniform mechanical properties and simultaneous enhancement of both strength and ductility. We demonstrate how this alloy can be modified by a single component to address unfavorable microstructures, providing a pathway to achieve desirable mechanical characteristics directly from 3D printing.

Manufacturing of high strength and high conductivity copper with laser powder bed fusion.

Additive manufacturing (AM), known as 3D printing, enables rapid fabrication of geometrically complex copper (Cu) components for electrical conduction and heat management applications. However, pure Cu or Cu alloys produced by 3D printing often suffer from either low strength or low conductivity at room and elevated temperatures. Here, we demonstrate a design strategy for 3D printing of high strength, high conductivity Cu by uniformly dispersing a minor portion of lanthanum hexaboride (LaB6) nanoparticles in pure Cu through laser powder bed fusion (L-PBF). We show that trace additions of LaB6 to pure Cu results in an improved L-PBF processability, an enhanced strength, an improved thermal stability, all whilst maintaining a high conductivity. The presented strategy could expand the applicability of 3D printed Cu components to more demanding conditions where high strength, high conductivity and thermal stability are required.

Designing against phase and property heterogeneities in additively manufactured titanium alloys.

Additive manufacturing (AM) creates digitally designed parts by successive addition of material. However, owing to intrinsic thermal cycling, metallic parts produced by AM almost inevitably suffer from spatially dependent heterogeneities in phases and mechanical properties, which may cause unpredictable service failures. Here, we demonstrate a synergistic alloy design approach to overcome this issue in titanium alloys manufactured by laser powder bed fusion. The key to our approach is in-situ alloying of Ti-6Al-4V (in weight per cent) with combined additions of pure titanium powders and iron oxide (Fe2O3) nanoparticles. This not only enables in-situ elimination of phase heterogeneity through diluting V concentration whilst introducing small amounts of Fe, but also compensates for the strength loss via oxygen solute strengthening. Our alloys achieve spatially uniform microstructures and mechanical properties which are superior to those of Ti-6Al-4V. This study may help to guide the design of other alloys, which not only overcomes the challenge inherent to the AM processes, but also takes advantage of the alloy design opportunities offered by AM.

Exercise Improved the Anti-Epileptic Effect of Carbamazepine through GABA Enhancement in Epileptic Rats.

Carbamazepine (CBZ) is an anticonvulsant drug that usually is used for the treatment of seizures. The anti-epileptic and the anti-epileptogenic effect of exercise has been reported, as well. This study was aimed to evaluate the synergic effect of combined therapy of exercise and CBZ in epileptic rats, as well as the alternation of the GABA pathway as a possible involved mechanism. The seizure was induced by pentylenetetrazol (PTZ) injection. Animals were divided into sham, seizure, exercise (EX), CBZ (25, 50 and 75), EX + CBZ (25, 50 and 75). Treadmill forced running for 30 min has been considered as the exercise 5 days per week for four weeks. CBZ was injected in doses of 25, 50 and 75 mg/kg, half an hour before seizure induction and 5 h after doing exercise in the animals forced to exercise. Seizure severity reduced and latency increased in the EX + CBZ (25) and EX + CBZ (50) groups compared to the seizure group. The distribution of GAD65 in both hippocampal CA1 and CA3 areas increased in the EX + CBZ (75) group. GABAA receptor α1 was up-regulated in the CA3 area of the EX + CBZ (75) group. The distribution of GAD65 in the cortical area increased in EX, EX + CBZ (50), CBZ (75) and EX + CBZ (75) groups. GABAA receptor α1 was up-regulated in the neocortex of EX + CBZ (50), CBZ (75) and EX + CBZ (75) groups. Our findings suggested that exercise has improved the efficacy of CBZ and reduced the anti-epileptic dose. The enhancement of GABA signaling might be involved in the synergistic effect of exercise and CBZ.

Role of miR153 and miR455-5p Expression in Oral Squamous Cell Carcinoma Isolated from Plasma.

BACKGROUND: Despite the notable advances in modern surgery and radiotherapy,no significant increase in the five year survival rate of oral squamous cell carcinoma has been reported. Collecting evidence demonstrates that miR 153 and miR 455-5p play a key role in growth and progression of oral cancer. Early detection of OSCC is important for enhancing patient quality of life and clinical treatment.For this reason, biomarkers or tumour markers offer an opportunity to intervene and avoid development of oral cancer. METHODS: A total of 50 blood samples from patients from both genders (25 OSCC and 25 healthy people/control groups) were obtained to determine the expression of miR153 and miR455-5p using Real time Polymerase chain reaction and t test. RESULTS: In general by using the formula Δ ct, it is evident that the miR 153 expression in peripheral blood is lower in patients than in healthy individuals (1.97) while the miR 455-5p expression in peripheral blood is higher in patients than in healthy individuals (2.56). CONCLUSION: We conclude that miR153 and miR 455-5p expression in serum can function as a diagnostic screening test for the early detection of oral squamous cell carcinoma.
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The effect of exercise on GABA signaling pathway in the model of chemically induced seizures.

AIMS: Gamma amino butyric acid (GABA) imbalance plays a critical role in most neurological disorders including epilepsy. This study assessed the involvement of mild exercise on GABA imbalance following by seizure induction in rats. MAIN METHODS: Seizure was induced by pentylentetrazole (PTZ) injection. Animals were divided into sham, seizure, exercise (EX), co-seizure-induced exercise (Co-SI EX) and Pre-SI EX groups. In the Co-SI EX group, doing exercise and seizure induction was carried out during four weeks. Animals in the Pre-SI EX group exercised in week 1 to week 8 and seizures were induced in week 5 to week 8. Seizure properties, neural viability and expressions of glutamic acid decarboxylase 65 (GAD65) and GABAA receptor α1 in the hippocampus were assessed. KEY FINDINGS: Seizure severity reduced and latency increased in the Co-SI EX and Pre-SI EX groups compared to seizure group. The mean number of dark neurons decreased in all exercise groups compared to seizure group in both CA1 and CA3 areas. The gene level of GAD65 and GABAA receptor α1 was highly expressed in the Co-SI EX group in the hippocampal area. Distribution of GAD65 in the both CA1 and CA3 areas increased in the EX and Co-SI EX groups. GABAA receptor α1 was up-regulated in the CA3 area of Co-SI EX group and down-regulated in the CA1 and CA3 areas of Pre-SI EX group. SIGNIFICANCE: These findings suggest that exercise develop anti-epileptic as well as neuroprotective effects by modulating of GABA disinhibition.

Applications of Propolis in Dentistry: A Review.

BACKGROUND: Propolis is a resinous substance obtained from the beehives that has antioxidant, anti-bacteria, anti-virus, anti-fungal, anti-tumor and anti-inflammatory activity. The aim of this study was to review the studies about the role of propolis in improving dental and oral health. METHODS: This study reviewed the published articles regarding the applications of propolis in dentistry. An electronic search of the literature was carried out in Farsi electronic databases including Google, Medlib.ir, SID, Iranmedex and Magiran as well as English electronic databases such as PubMed and ISI Web of Knowledge. These databases were searched for articles published between 1997 and October 20, 2017. Non-dental books and journals were also manually searched. RESULTS: This study reviewed published articles on the efficacy of propolis for surgical wound healing, caries prevention, treatment of dentin hypersensitivity, treatment of aphthous ulcers and propolis as a storage medium for avulsed teeth, root canal irrigating solution and mouthwash. CONCLUSION: The result of the reviewed article showed that propolis is effective an agent that is used for multiple purpose in oral health.

Bone Allograft: An Option for Total Mandibular Reconstruction.

Total mandibular reconstruction is one of the most challenging modalities in maxillofacial surgery. In this article, we try to introduce a method of total mandible reconstruction. We report a 25-year-old male patient with complete involvement of the mandible by Langerhans cell tumor. The patient underwent total mandibulectomy and reconstruction with bone allograft harvested from a donor who had died the day before. The patient has good functional and aesthetic results in a long time. It seems that bone allograft can be a good alternative to other methods in total mandibular reconstruction.

Cephalometric risk factors of obstructive sleep apnea.

INTRODUCTION: Previous studies on risk factors of obstructive sleep apnea (OSA) are highly controversial and mostly identifying a few cephalometric risk factors. METHODS: OSA diagnosis was made according to the patients' apnea-hypopnea index (AHI). Included were 74 OSA patients (AHI > 10) and 52 control subjects (AHI ≤ 10 + free of other OSA symptoms). In both groups, 18 cephalometric parameters were traced (SNA, SNB, ANB, the soft palate's length (PNS-P), inferior airway space, the distance from the mandibular plane to the hyoid (MP-H), lengths of mandible (Go-Gn) and maxilla (PNS-ANS), vertical height of airway (VAL), vertical height of the posterior maxilla (S-PNS), superior posterior airway space (SPAS), middle airway space, distances from hyoid to third cervical vertebra and retrognathion (HH1), C3 (C3H), and RGN (HRGN), the maximum thickness of soft palate (MPT), tongue length (TGL), and the maximum height of tongue). These parameters were compared using t-test. RESULTS: Significant variables were SPAS (p = 0.027), MPT, TGL, HH1, C3H, HRGN, PNS-P, S-PNS, MP-H, VAL, and Go-Gn (all p values ≤ 0.006). CONCLUSION: OSA patients exhibited thicker and longer soft palates, hyoid bones more distant from the vertebrae, retrognathion, and mandibular plane, higher posterior maxillae, longer mandibles, and smaller superior-posterior airways.

Cephalometric risk factors associated with myocardial infarction in patients suffering from obstructive sleep apnea: A pilot case-control study.

INTRODUCTION: Obstructive sleep apnea (OSA) and its craniofacial anatomic risk factors might play a role in several cardiovascular diseases, including myocardial infarction (MI). However, there are no data about cephalometric findings among OSA patients with MI. METHODS: In this pilot case-control study, about 2000 individuals referred to the sleep center were evaluated according to apnea - hypopnea index (AHI) and other inclusion criteria. Included were 62 OSA male patients (AHI > 10), of whom 6 had an MI history. In both control (n = 56) and MI groups (n = 6), 18 cephalometric parameters were traced. Data were analyzed using independent samples t-test. RESULTS: Compared with control OSA patients, OSA patients with MI showed a significantly larger tongue length (p = 0.015). The other cephalometric variables were not significantly different between the two groups. CONCLUSION: An elongated tongue might be considered a risk factor for MI in OSA patients. The role of other variables remains inconclusive and open to investigation with larger samples (determined based on pilot studies such as this report) collected in longitudinal fashion.

Anticonvulsant and neuroprotective effects of Pimpinella anisum in rat brain.

BACKGROUND: Essential oil of Pimpinella anisum L. Apiaceae (anise oil) has been widely used in traditional Persian medicine to treat a variety of diseases, including some neurological disorders. This study was aimed to test the possible anti-seizure and anti-hypoxia effects of anise oil. METHODS: The effects of different concentrations of anise oil were tested on seizure attacks induced by pentylenetetrazol (PTZ) injection and neuronal hypoxia induced by oxygen withdrawal as well as on production of dark neurons and induction of long-term potentiation (LTP) in in vivo and in vitro experimental models of rat brain. RESULTS: Anise oil significantly prolonged the latency of seizure attacks and reduced the amplitude and duration of epileptiform burst discharges induced by injection of intraperitoneal PTZ. In addition, anise oil significantly inhibited production of dark neurons in different regions of the brain in epileptic rats. Anise oil also significantly enhanced the duration of the appearance of anoxic terminal negativity induced by oxygen withdrawal and inhibited induction of LTP in hippocampal slices. CONCLUSIONS: Our data indicate the anticonvulsant and neuroprotective effects of anise oil, likely via inhibition of synaptic plasticity. Further evaluation of anise oil to use in the treatment of neurological disorders is suggested.