Local structure of layered oxide electrode materials for lithium-ion batteries

Li-ion batteries are promising candidates for electrical energy storage in applications ranging from portable electronics to hybrid and electric vehicles. In this context, layered compounds in the Li(1+delta)(TM(x)Mn(1-x))(1-delta)O(2) family (TM = transition metal) have received much attention due to their high capacity and stability. In this Research News article we describe recent advances on structural characterization of Li-ion electrode materials using state-of-the-art electron microscopy. Direct evidence of the monoclinic nature of Li(2)MnO(3) has been provided. It has been demonstrated that differences in Z-contrast imaging between Li(2)MnO(3) and LiTMO(2) may be used to screen samples for phase separation in the 10-100 nm scale.

Clinical, neurophysiologic, neuropsychological findings and short genetic analysis in patients with idiopathic Parkinson's disease

The aim of this paper is to analyze the results of correlation of clinical symptoms and their characteristics with the results of neurophysiologic, neuropsycologic investigations and short genetic analyses in patients with Idiopathic Parkinson's disease (IPD).

MATERIAL AND METHODS

The paper is a prospective and retrospective study of 15 IPD patients and 25 patients with different forms of parkinsonism.

RESULTS

Patients with idiopathic Parkinson's disease had all cardinal symptoms characteristic for the disease: tremor, rigidity and reduced postural reflexes in 100%.

CONCLUSION

Clinical, neurophysiologic, neuropsychologic and neuroimaging methods of investigations showed changes that are nonspecific in proportions corresponding to those in available literature (Tab. 3, Fig. 2, Ref. 11).

[Adjuvant and individual application of lumbar sympathectomy at patient with arterial disease in lower limb]

The first lumbar sympathectomy for treatment of arterial occlusive disease of the lower extremity was performed in 1924 by Julio Diez of Buenos Aires. The standart anatomy textbooks indicate, as a rule that the lumbar sympathetic trunk contains four or five ganglia. The overall anatomic denervation is important for achievement of an adequate sympathectomy of a given segment of an extremity. Criteria and indications for complete sympathetic block are still not clear. Exceptionally important for the improvement of the reology of the lower limbs is the option for a direct increase of the collaterals' debit which could be achieved by extensive profundoplasty. As an addition to the arterial reconstructions, the sympathectomy increases the passability of small vessel anastomosis and the recovery of traumatized arteries. Unilateral or bilateral lumbar sympathectomy is performed by retroperitonal access. From 01.01.2008 till 01.11.2008 in our clinic were performed 117 isolated and after arterial reconstruction lumbar sympathectomies.

[Surgical treatment for stenotic lesion of the subclavian artery]

We present a case of a 56-year-old male patient who was admitted at the clinic with complains of pain and blue-colored index finger of the left hand since a couple of days. He has an anamnesis of claudication of the left arm. After the contrast CT-angiogram, which showed a 80% stenosis of the left subclavian artery, the patient had an allergic reaction. This changed our initial plan for an endovascular intervention and we proceeded to an open surgical procedure. Because of the suitable anatomical characteristics we did a replantation of the subclavian artery to the common carotid artery. The postoperative period went smoothly. Six months after the intervention the patient is feeling fine. He has pulse on the radial and ulnar arteries and no sign of the necrosis of the index linger. Subclavian-carotid transposition is a safe method for the treatment of steno-occlusive lesions of the subclavian artery. Except the ortograde physiological blood flow through the vertebral artery and the construction of only one anastomosis, the main advantage over the bypass surgery is not using autogenous or heterogenous prosthetic material.

Detection of single atoms and buried defects in three dimensions by aberration-corrected electron microscope with 0.5-A information limit

The ability of electron microscopes to analyze all the atoms in individual nanostructures is limited by lens aberrations. However, recent advances in aberration-correcting electron optics have led to greatly enhanced instrument performance and new techniques of electron microscopy. The development of an ultrastable electron microscope with aberration-correcting optics and a monochromated high-brightness source has significantly improved instrument resolution and contrast. In the present work, we report information transfer beyond 50 pm and show images of single gold atoms with a signal-to-noise ratio as large as 10. The instrument's new capabilities were exploited to detect a buried Sigma3 {112} grain boundary and observe the dynamic arrangements of single atoms and atom pairs with sub-angstrom resolution. These results mark an important step toward meeting the challenge of determining the three-dimensional atomic-scale structure of nanomaterials.

[Endovascular procedures in case of cancers engaging the vessels of the small pelvis]

Cervix cancer is quite common nowadays. Its progress is followed by painful symptomatology, urosepsis, lymphedem, flebothrombosis and ischemia of the lower limbs. The surgical treatment and the following chemotherapy and radiotherapy causes proliferation of the fibroid tissue, which embraces and presses the vessels of the small pelvis. We are to depict two clinical cases in which the choice of the percutaneous transluminal angioplasty and the implementation of a covered stent - graft is preferable to the open surgery. During the predilatation with a balloon catheter, our first patient suffered of a vessel rupture, visualized on the intraoperative angiogram. The rupture of vessel during angioplasty usually demands open surgical correction, but endovascular procedure can provide a fast, efficient, and less aggressive method. Covered stent-grafts are applicable for both treatment and stabilization of vessel lesions.

Sublimation of atomic layers from a chromium surface

We employ low-energy electron microscopy to study the kinetics of thermal etching, or sublimation, of Cr(001) at approximately 1100 K. Atomic layers are removed from the surface by spontaneous nucleation and growth of two-dimensional vacancy islands, by rotation of spiral steps, and by island decay. The growth rates of vacancy islands and the rotation frequencies of double spirals are measured as a function of temperature, and the results are correlated with activation barriers of surface processes. Mass transport between the surface and bulk is shown to be unimportant.

The objective severity assessment of atopic dermatitis (OSAAD) score: validity, reliability and sensitivity in adult patients with atopic dermatitis

BACKGROUND

The Objective Severity Assessment of Atopic Dermatitis (OSAAD) score is a recently developed scale for evaluation of severity of atopic dermatitis, constructed from the assessment of epidermal barrier function, and properties using noninvasive bioengineering methods and computer-assisted estimates of disease extent. The method has been validated for use in infants and children with atopic dermatitis and compared with a referent scoring system.

OBJECTIVES

The aim of the present study was to test the validity, reliability and sensitivity of the OSAAD score as an objective tool for the assessment of the severity of atopic dermatitis in adult patients.

METHODS

Thirty-two adult patients with atopic dermatitis were included in the study. To assess the validity of the OSAAD score we tested it against the Severity Scoring of Atopic Dermatitis (SCORAD) index of the European Task Force on Atopic Dermatitis as a referent clinical severity scale, and the serum levels of interleukin (IL)-16 as a laboratory variable for monitoring the activity of atopic dermatitis. Responsiveness to change was assessed in a longitudinal study comparing OSAAD, SCORAD and serum levels of IL-16 before and after treatment. To test the reliability of the OSAAD score we studied the interobserver variability of the score recorded by three independent board-certified dermatologists in 16 patients and compared it with SCORAD.

RESULTS

We report a significant correlation between the OSAAD and the SCORAD index as an acknowledged referent severity scale. The OSAAD score correlated significantly with the serum levels of IL-16 in the acute stage of atopic dermatitis. In a longitudinal study, the OSAAD score decreased significantly, parallel with improvement of the skin findings and a significant decrease in the SCORAD score and IL-16 serum levels. We report improved interobserver variability for the OSAAD score compared with SCORAD.

CONCLUSIONS

This is the first study validating the OSAAD score as a sensitive and reliable tool for the assessment of the severity of atopic dermatitis in adult patients.

Directed self-assembly of Ge nanostructures on very high index, highly anisotropic Si(hkl) surfaces

Families of very high-index planes, such as those which bifurcate spontaneously to form a hill-and-valley structure composed of opposing facets, provide natural templates for the directed growth of position-controlled self-organized nanostructures with shapes determined by the facet width ratio R. For example, deposition of a few ML of Ge on Si(173 100 373), corresponding to R(113/517) = 1.7, results in a field of 40-nm-wide Ge nanowires along [72 187] with a uniform period of 60 nm.

[Initial experience in endovascular treatment of abdominal aortic aneurysms in Bulgaria]

The abdominal aneurysm imposes prominent epidemiological impact due to its high incidence and life threatening complications. The first steps in endovascular treatment of abdominal aneurysms in Bulgaria are herein described. Five bifurcated and one straight stent-grafts were implanted in the ,,St.Ekaterina" University Hospital for the period from February till May 2004. Satisfactory therapeutic result was achieved in all cases. The continuing follow-up of the patients proved favorable tolerability. The good therapeutic response, lack of perioperative mortality, and low complication rate provide evidence that endovascular repair can have beneficial implication in patients with abdominal aneurysms and high operative risk.

Dislocation-driven surface dynamics on solids

Dislocations are line defects that bound plastically deformed regions in crystalline solids. Dislocations terminating on the surface of materials can strongly influence nanostructural and interfacial stability, mechanical properties, chemical reactions, transport phenomena, and other surface processes. While most theoretical and experimental studies have focused on dislocation motion in bulk solids under applied stress and step formation due to dislocations at surfaces during crystal growth, very little is known about the effects of dislocations on surface dynamics and morphological evolution. Here we investigate the near-equilibrium dynamics of surface-terminated dislocations using low-energy electron microscopy. We observe, in real time, the thermally driven nucleation and shape-preserving growth of spiral steps rotating at constant temperature-dependent angular velocities around cores of dislocations terminating on the (111) surface of TiN in the absence of applied external stress or net mass change. We attribute this phenomenon to point-defect migration from the bulk to the surface along dislocation lines. Our results demonstrate that dislocation-mediated surface roughening can occur even in the absence of deposition or evaporation, and provide fundamental insights into mechanisms controlling nanostructural stability.

Coherent nano-area electron diffraction

We describe the new coherent nano-area electron diffraction (NED) and its application for structure determination of individual nanostructures. The study is motivated by the challenge and the general lack of analytical techniques for characterizing nanometer-sized, heterogeneous phases. We show that by focusing electrons on the focal plane of the pre-objective lens using a 3rd condenser lens and a small condense aperture, it is possible to achieve a nanometer-sized highly parallel illumination or probe. The high angular resolution of diffraction pattern from the parallel illumination allows over-sampling and consequently the solution of phase problem based on the recently developed ab initio phase retrieval technique. From this, a high-contrast and high-resolution image can be reconstructed at resolution beyond the performance limit of the image-forming objective lens. The significance of NED for nanostructure characterization will be exemplified by single-wall carbon nanotubes and small metallic clusters. Imaging from diffraction patterns, or diffractive imaging, will be demonstrated using double-wall carbon nanotubes.

Verrucous carcinoma of the axilla: case report and review

BACKGROUND

Verrucous carcinoma, a variant of squamous cell carcinoma, is distinct from squamous cell carcinoma in morphology and behavior. It preferentially occurs on the oropharyngeal mucosa, the urogenital mucosa, and the soles. In contrast to its malignant clinical picture, the tumor grows locally invasive but is histologically benign and metastasizes rarely.

METHODS

We report the uncommon occurrence of a large verrucous carcinoma on apparently uninvolved skin in the right axilla in a 47-year-old male.

RESULTS

Histologic examination reveals a cauliflower-like tumor consisting of deep invaginated epidermal proliferation with rabbit burrow-like, keratin-filled sinus formations; the basement membrane, however, remains intact. Immunohistology showed positivity for pancytokeratin (KL-1) and cytokeratin (CK) 18 and negativity for CK7, and assessment of the proliferative activity of the tumor cells revealed low percentage of Ki-67 expression. Furthermore, there were only scattered cells expressing p53 or bcl-2. Polymerase chain reaction excluded the presence of human papillomavirus. After complete excision, no signs of recurrence occurred over a follow-up period of three years.

CONCLUSION

Verrucous carcinoma should be distinguished from typical squamous cell carcinoma. The clinicopathological features, differential diagnosis, and therapy are discussed here together with the molecular biologic aspects of the tumor.

[Angioplasty and stenting of extracranial cerebral vessels]

The stroke is one of the major causes for death and invalidization in the modern society. In about 30% of the cases the stroke is attributed to stenosis of a supraaortic vessel. In the last few years the percutaneous angioplasty and stenting is an alternative method of the classical surgical treatment--the carotid thrombendarterectomy. Crucial moment in the evolution of the method is the introduction in the practice of the systems for distal embolic protection of the brain and the routine implantation of stents with new design. One of the main conditions for successful and noncomplicated stenting is the respect of a strict procedural protocol. In the article we present the results of 17 cases with angioplasty and stenting of supraaortic vessels performed in our Clinic in the period 07.02.2001-01.07.2001. The immediate success rate is 100%. No major complications (stroke, myocardial infarction and death) were registered. In the midterm follow-up there were no thrombosis and restenosis of the implanted stents. We present four interesting case reports: 1. One stage stenting of right coronary artery and right internal carotid artery, 2. Stenting of a subocclusive right internal carotid stenosis with balloonexpandable stent and 3. Stenting of a vertebral artery as the unique brain supplying vessel and 4. Stenting of subocclusive aortoostial lesion of the brachiocephalic trunk in a patient with totally occluded contralateral internal carotid artery.

CONCLUSIONS

Stenting of supraaortic vessels is a safe and reliable method when performed by experienced operator and when are applied the ultimate methods of cerebral protection and the new stent designs. The carotid stenting is a reliable alternative of the surgery and gains more and more popularity.

[The first case of one stage endovascular treatment of the stenosis in the celiac trunk, bilateral renal arteries, and right common iliac arteries]

Although not very often diagnosed, the acute and chronic mesenterial ischemia is advancing and life threatening condition. When associated with multivascular pathology compromising the perfusion and causing multiple organ failure the choice of treatment is a challenge. In such cases the radical surgical treatment is associated with high morbidity and mortality. In recent years endovascular methods of treatment (angioplasty and stenting) are gaining popularity in the treatment of these patients. We report a case of chronic mesenteric ischemia that caused abdominal angina and weight loss in a 63-year-old man with renovasal hypertension, renal insufficiency and peripheral vascular disease. Angiographic study revealed multivascular pathology including total occlusion of the superior mesenteric artery, 90% stenosis of the celiac trunk, bilateral high grade renal stenoses and obstructive pathology of both iliac arteries. One stage successful endovascular treatment was performed in the three vascular territories. In the Celiac trunk, left renal artery and right common iliac artery were implanted stents. A double right renal artery was treated successfully with kissing balloon. A clinical follow-up demonstrated success with no recurrence of abdominal pain, body weight gain, better control of the hypertension and improvement of the renal function. This is the first reported case of one stage endovascular treatment of a visceral artery, bilateral renal arteries and iliac artery. This case report illustrates the value of endovascular treatment in a patient with atherosclerotic narrowing of multiple abdominal visceral arteries.

[Endovascular therapy of acute traumatic vascular peripheral dissections using self-expandable stents]

Percutaneous peripheral and coronary interventions as well as surgical procedures can be complicated by dissections and traumatic lesions of peripheral arteries. Posttraumatic peripheral dissections can be threatening for the extremities and often their management might be a challenge. Open surgery requires wide exposure and dissection of posttraumatic tissues. Endovascular techniques using selfexpandable stents gains popularity because of high efficiency, safety and good results. This technique is associated with decreased trauma, no requirements for anesthesia, short hospital stay. We present two cases of posttraumatic iliac dissections treated with self expandable stents.