Origin of photocatalytic activity enhancement in Pd/Pt-deposited anatase N-TiO2- experimental insights and DFT study of the (001) surface.

In pursuit of the ideal photocatalyst, cheap and stable semiconductor TiO2 is considered to be a good choice if one is able to reduce its band gap and decrease the recombination rate of charge carriers. The approach that offers such improvements for energy conversion applications is the modification of TiO2 with nitrogen and noble metals. However, the origin of these improvements and possibilities for further design of single-atom catalysts are not always straightforward. To shed light on the atomic-scale picture, we modeled the nitrogen-doped (001) anatase TiO2 surface as a support for palladium and platinum single-atom deposition. The thermodynamics of various synthesis routes for Pd/Pt deposition and nitrogen doping is considered based on density functional theory (DFT)-calculated energies, highlighting the effect of nitrogen doping on metal dimer formation and metal-support interaction. XPS analysis of the valence band of the modified TiO2 nanocrystals, and the calculated charge transfer and electronic structure of single-atom catalysts supported on the (001) anatase TiO2 surface provide an insight into modifications occurring in the valence zone of TiO2 due to nitrogen doping and Pd/Pt deposition at the surface. DFT results also show that substitutional nitrogen doping significantly increases metal-support interaction, while interstitial nitrogen doping promotes only Pt-support interaction.

Modification of N-doped TiO2 photocatalysts using noble metals (Pt, Pd) - a combined XPS and DFT study.

Nitrogen-doped TiO2 (N-TiO2) is considered as one of the most promising materials for various photocatalytic applications, while noble metals Pd and Pt are known as good catalysts for hydrogen evolution. This work focuses on the determination of structural and electronic modifications of N-TiO2, achieved by noble metal deposition at the surface, as a starting indicator for potential applications. We focus on the properties of easily synthesized nanocrystalline nitrogen-doped anatase TiO2, modified by depositing small amounts of Pd (0.05 wt%) and Pt (0.10 wt%), aiming to demonstrate efficient enhancement of optical properties. The chemical states of dopants are studied in detail, using X-ray photoemission spectroscopy, to address the potential of N-TiO2 to act as a support for metallic nanoparticles. DFT calculations are used to resolve substitutional from interstitial nitrogen doping of anatase TiO2, as well as to study the combined effect of nitrogen doping and oxygen vacancy formation. Based on the binding energies calculated using Slater's transition state theory, dominant contribution to the N 1s binding energy at 399.8 eV is ascribed to interstitially doped nitrogen in anatase TiO2. Given that both structure and photocatalytic properties depend greatly on the synthesis procedure, this work contributes further to establishing correlation between the structure and optical properties of the noble metal modified N-TiO2 system.

Does the presence of an unerupted lower third molar influence the risk of mandibular angle and condylar fractures?

It has been suggested that unerupted lower third molars (M3) increase the fragility of the mandibular angle and simultaneously decrease the risk of condylar fracture. However, it is unknown whether this applies regardless of the direction and point of impact of the traumatic force. The aim of this study was to investigate the impact of an unerupted M3 on the fragility of the angle and condyle in terms of a force acting from different directions and affecting different regions of the mandible. Computed tomography scans of a human mandible and finite element methodology were used to obtain two three-dimensional models: a model with, and the other without an unerupted M3. A force of 2000N was applied to three different regions of the models: the symphysis, ipsilateral body, and contralateral body, respectively. When the force was applied to the mandibular body, the results revealed increased angle fragility in cases with unerupted M3. When the force was applied to the symphysis, the condyle region showed higher fragility, irrespective of the presence of an unerupted M3. In summary, fragility of the angle and condyle regions depends on the presence of an unerupted M3 and on the direction and point of impact of the force.

Paranasal sinus osteoma: is there any association with anatomical variations?

BACKGROUND: Developmental disturbances of the paranasal sinuses are proposed as the cause of osteoma. We examined whether such disturbances may result in the frequent presence of anatomical variations of the paranasal sinuses in patients with osteoma. METHODOLOGY/PRINCIPAL: The study was performed retrospectively on 2,820 patients subjected to CT examination during 2005 - 2011. Demographic and CT characteristics of osteoma, and associated pathological findings were evaluated for 104 patients with diagnosed osteoma. The presence of anatomical variations was assessed for 51 osteoma patients with a complete medical history, and for 1,233 patients from a control group. RESULTS: The prevalence of osteomas was found to be 3.69%, with male to female ratio 1.08:1. The frontal sinus was most commonly affected. The presence of anatomical variations was more frequent in patients with osteoma than in controls, with significant differences confirmed for the sphenomaxillary plate, infraorbital cell, and crista galli pneumatization. CONCLUSIONS: The paranasal sinus osteoma is associated with higher prevalence of anatomical variations. This can be explained either by the stronger influence of genetic and/or environmental factors on the development of the paranasal sinuses in patients with osteoma, or by their higher susceptibility to above mentioned factors.

Incidence of brain metastases in early stage HER2 3+ breast cancer patients; is there a role for brain CT in asymptomatic patients?

PURPOSE: Human epidermal growth factor receptor 2 overexpression (HER2 3+) is reported in retrospective studies as a factor that contributes to higher incidence of brain metastases (BM) in patients with metastatic breast carcinoma. Although there are some reports suggesting higher incidence of BM in adjuvant trastuzumab trials, the true incidence, as well as the time of occurrence of BM in early-stage high risk breast carcinoma patients, has not been widely prospectively explored. The main objective of this study was to prospectively explore the incidence of BM during and after adjuvant trastuzumab administration in HER2 3+ early-breast carcinoma patients. METHODS: Two hundred and fifty-eight patients with early, HER2 3+ breast carcinoma have been included in this analysis. Brain computed tomography (CT) scan was scheduled once during adjuvant trastuzumab therapy and thereafter only if central nervous system (CNS) symptoms occurred. RESULTS: Eighty-five patients (33%) underwent brain CT in the absence of CNS symptoms. The median number of trastuzumab cycles at the time of brain CT was 9 (range 4-18). There were no BM detected by brain CT in these 85 asymptomatic patients. However, during a median follow up of 18 months 5/258 patients (1.93%) developed BM, but only 2 (0.77%) while still receiving adjuvant trastuzumab. The median time from breast cancer diagnosis to BM was 24 months (range 14-43). CONCLUSION: BM are a rare event during adjuvant trastuzumab treatment and brain CT screening is not justified in asymptomatic patients with early HER2 3+ breast carcinoma.

Local control of glomus tumors of the head & neck by radiation therapy and surgery.

PURPOSE: Glomus tumors are rare tumors, highly vascular and typically radiosensitive. Therapeutic options include surgery, radiation therapy (RT), embolisation or any combination of them, but the appropriate treatment still remains a challenge. The purpose of this study was to report the results of local control of 7 patients with glomus tumors treated with surgery and external beam RT (EBRT). METHODS: All of the patients underwent primary surgery and then postoperative EBRT. Follow-up was calculated from the date of initiation of EBRT and ranged from 3 to 15 years (mean 7.14, median 6.2). The likelihood of local control was analysed using the Kaplan-Meier product limit method. We also analysed the average duration of response between two groups of patients with different doses of EBRT as well as the presence of acute and late EBRT complications. RESULTS: Local control was obtained in 6/7 (85.7%) patients. Moreover, local control was achieved in 3/4 (75%) patients with recurrent glomus tumors, while in patients with postoperative residual disease local control was obtained in 3/3 (100%) of them. Patients who received <50 Gy (n=2) had shorter average duration of response compared to patients who received >50 Gy (n=5; p=0.248). There were no severe treatment complications. CONCLUSION: Surgery and RT represent an appropriate treatment approach for advanced glomus tumors with acceptable complications.

Invasive inflammatory pseudotumor of the pelvis: a case report with review of the literature.

Inflammatory pseudotumor (IPT) is a rare benign lesion of unknown etiology, which mimics malignant neoplasm and may arise from various organs. A 53-year-old woman was submitted to diagnostic evaluation because of bilateral, hydroureteronephrosis and oedema of the left leg after a 3-month history of fever of unknown origin. On bimanual vaginal and rectal examination, a mass was involving the uterus, parametria and mostly left adnexa, while the cervix appeared normal. Computed tomographic (CT) scan revealed a 13x10.5 cm mass in the pelvis, mostly at the place of the left adnexa, uterus and both parametria, also involving the surrounding tissues and producing bilateral hydroureteronephrosis. At laparotomy, a grey solid mass was seen, mainly involving the reproductive system. As no radical operation could be performed, the mass was only biopsied and histology showed an inflammatory pseudotumor. Antibiotic therapy was given for one month. Follow-up CT 4 and 8 months after laparotomy showed local regression of IPT. The last follow-up CT, 20 months after laparotomy, revealed no evidence of tumor.

Surface roughness of ultra-thin silver films sputter deposited on a glass.

Silver was sputter deposited on a glass with a thin film thickness ranging from 10 to 80 nm. Scanning tunnelling microscopy was used to study the morphology of the obtained Ag-glass surfaces and to estimate the surface roughness. An equation for the surface roughness of the thin film was evaluated using parameters related to the thin film features: the surface roughness of the substrate, the compressibility of the thin film and the film thickness. The experimental results were fitted using the evaluated equation, and the conditions favouring lower or higher surface roughness were analyzed.

Surface resistivity estimation by scanning surface potential microscopy.

Nickel was sputter deposited on a glass with a thin film thickness of 600 nm under either in an argon atmosphere or under a partial pressure of nitrogen of either 1.3 x 10(-4) or 4 x 10(-4) mbar. Atomic force microscopy and scanning surface potential microscopy (SSPM) were used to study the morphology and to estimate the surface resistivity of the obtained Ni thin films taking into account surface-roughness effects. For the three samples investigated, the surface resistivity values as estimated using SSPM were in good agreement with the results obtained by standard four-point probe measurements.

Patient-physician relationship in the aftermath of war.

During the period of conflict that led to the dissolution of the former Yugoslavia, the Serbian healthcare system suffered greatly; as a result, relationships between physicians and their patients reached an all-time low. After cessation of the various wars, a group of medical students attempted to assess the state of the patient-physician relationship in Serbia. Their study showed a relationship characterised by very meek patients and rather arrogant physicians. Empowered by their engagement, the medical students constructed a set of standards for achieving a proper patient-physician relationship; physicians should be capable of hearing and understanding patients, with the result that the ensuing empowerment can enable patients and physicians to create a tool for changing the relationship between both parties.

Gunshot injury to the face with a missile lodged in the upper cervical spine without neurological deficit.

An unusual case of facial gunshot injury with the missile lodged in the cervical spinal canal, but without any neurological impairment is reported. The extent of tissue damage and missile track termination in a male patient who sustained gunshot trauma to the face was assessed by plain radiography and by CT scans. The patient was treated conservatively and observed for clinical manifestations of neurological deficit for 3 weeks. CT of the head and neck performed 13 years after injury with the three-dimensional (3D) reconstruction of skeletal elements revealed healed fractures of the right nasal bone, the labyrinth of the right ethmoid bone, and position of the missile on the medial aspect of the right lateral mass of the atlas. There was no migration of the missile during this period. This case report of gunshot wound to the face associated with injury of the cervical spine indicated possibility of survival and atypical absence of clinical manifestation that may occur even when a bullet remains in the spinal canal.