Showing 1–12 of 72 results
A Combined Gate Replacement and Input Vector Control Approach for Leakage Current Reduction
Input vector controlرایگان!
Input vector control (IVC) is a popular technique for leakage power reduction. It utilizes the transistor stack effect in CMOS gates by applying a minimum leakage vector (MLV) to the primary inputs of combinational circuits during the standby mode. However, the IVC technique becomes less effective for circuits of large logic depth because the input vector at primary inputs has little impact on leakage of internal gates at high logic levels. In this paper, we propose a technique to overcome this limitation by replacing those internal gates in their worst leakage states by other library gates while maintaining the circuit’s correct functionality during the active mode. This modification of the circuit does not require changes of the design flow, but it opens the door for further leakage reduction when the MLV is not effective. We then present a divide-and- conquer approach that integrates gate replacement, an optimal MLV searching algorithm for tree circuits, and a genetic algorithm to connect the tree circuits. Our experimental results on all the MCNC91 benchmark circuits reveal that 1) the gate replacement technique alone can achieve 10% leakage current reduction over the best known IVC methods with no delay penalty and little area increase; 2) the divide-and-conquer approach outperforms the best pure IVC method by 24% and the existing control point insertion method by 12%; and 3) compared with the leakage achieved by optimal MLV in small circuits, the gate replacement heuristic and the divide-and-conquer approach can reduce on average 13% and 17% leakage, respectively.
A double-blind controlled study of a nonhydroquinone bleaching cream in the treatment of melasma
Background Melasma iرایگان!
Background Melasma is an acquired hypermelanosis predominantly affecting the face of women. It is often recalcitrant to treatment with hypopigmenting agents. Objective To assess the efficacy of a nonhydroquinone cream (Amelan M®) vs. another (Mela-D®) as treatment for melasma. Methods Twenty-two French women with bilateral epidermal and/or mixed melasma were enrolled in a split-faced prospective trial lasting 4 months during summer season weeks. Twelve patients applied once-daily Amelan M® to one side of the face with sun-protective factor 60 UVA sunscreen each morning and Mela-D® once-daily to the other side of the face. Pigmentation was measured objectively using a mexameter and the melasma area and severity index (MASI) were measured subjectively. Results The mean decrease of pigmentation was statistically significant on the MASI with both cream and only with Amelan M with the mexameter. Some adverse side effects were observed. Conclusions Amelan M® is really more effective than Mela D® cream on melasma. Even though some side effects were observed patients preferred the Amelan M-treated side.
A New Approach to Stone-reliefs of Persepolis
In the north easternرایگان!
In the north eastern part of the Persian Gulf in Iran, there is a region called Fars today and Parse in the past. In this mountainous region there is a mountain previously called Mehr (love) and now called Rahmat (Mercy) with a 2500 years old ruined palace still dazzling on its skirts, remaining from the Achaemenid reign over Iran from c.550 to 330BC. Despite considerable research on the religion of this dynasty, Iranologists have not still conclusively reached a definite opinion on this matter and if they have, it is based on questionable evidences and interpretations. Based on remaining inscriptions and stone-carvings of this monument, the article is an attempt to show that the kings of this dynasty were definitely followers of Zoroaster, who founded the first official religion of the world 6 to 7 centuries AD, with all the symbols found in this unique palace having Iranian roots which so far have wrongly been attributed to the beliefs of other peoples and civilizations.
A practical, algorithmic approach to diagnosing hair shaft disorders
The hair shaft is aرایگان!
The hair shaft is a unique structure composed of an inner cortex and a protective outer cuticle. Any defects in this normal structure due to genetics or the environment can lead to variations in physical properties. Thus one should suspect a hair shaft disorder if a patient presents with an abnormality or change in hair texture, appearance, manageability or ability to grow hair long. A key feature of the clinical evaluation is to determine whether there is hair breakage (increased fragility) by looking for broken hairs and performing a tug test. Once this determination is made, an algorithmic approach can be used to narrow the differential diagnosis: hair shaft disorders with and without fragility. A hair mount along with other directed questions and examination will almost always allow the clinician to make an in-office diagnosis. Common case scenarios, photographs, and practical tips are provided to illustrate the use of this algorithmic approach in the diagnosis of hair shaft disorders. We have also included a summary of the molecular defects where known, which can be helpful in providing a correlation with clinical findings, in counseling patients, and potentially offering treatment options.
Abnormalities in the Adrenergic Control and the Rate of Lipolysis in Isolated Human Subcutaneous Adipose Tissue in Diabetes Mellitus
Subcutaneous adipose tissue was obtained from 9 patients with untreated diabetes mellitus and from 13 obese nondiabetics. After incubation with isoprenaline or noradrenaline, glycerol release and tissue cyclic AMP (cAMP) were determined. Basal glycerol release was twice as rapid from the diabetic adipose tissue. With isoprenaline, the cAMP concentration and the glycerol production was significantly higher in the diabetic adipose tissue. Noradrenaline did not increase glycerol production or cAMP concentration in the diabetic adipose tissue. Subcutaneous adipose tissue was also removed from the diabetics after antidiabetic treatment. Basal lipolysis was significantly reduced and noradrenaline significantly increased both glycerol release and cAMP production. With isoprenaline, cAMP production and glycerol release were significantly less after antidiabetic treatment than in the untreated state. The data provide evidence for increased a- as well as fl-adrenergic receptor sensitivity in human subcutaneous adipose tissue of untreated diabetic patients.
Acute Abdomen: Clinical Assessment and Decision-Making
An acute abdomen isرایگان!
An acute abdomen is usually defined as an acute abdominal pain of short duration which requires a decision on whether to proceed or not with urgent intervention . All abdominal crises present with one or more of five main symptoms or signs: pain, vomiting, abdominal distension, muscular rigidity, or shock. The severity and the order of occurrence of the symptoms are important for diagnosis, together with the presence or absence of fever, diarrhea, constipation, and others . The presence of tenderness on palpation is a hallmark of potential acute abdominal problem of surgical importance, and it generally implies inflammation of the visceral peritoneum. This tenderness may be accompanied or not by muscular rigidity (defense guarding or guarding). There are several grades of muscular rigidity, and its elucidation is not always easy on clinical exam, with the exception of the board-like rigidity typical of perforated ulcer. This guarding usually implies inflammation of the parietal peritoneum. Sometimes it takes a great deal of clinical acuity and experience to differentiate between voluntary and involuntary guarding. Modern abdominal imaging, interventional radiology, a better understanding of the natural history of many acute conditions, and more effective ntibiotic treatments have revolutionized emergency abdominal surgery and certainly improved our decision- making capabilities.
Acute Care General Surgery
Patients who presentرایگان!
Patients who present with emergency general surgical problems often have profound physiologic derangements that require immediate correction and stabilization prior to planning a diagnostic approach. This varies from the classic approach we were taught that culminates in history taking, formulating a differential diagnosis, obtaining laboratory and imaging studies, and initiating treatment. The acute care surgeon should be aggressive, take ownership, and promptly begin treatment often without having all the information in these situations. The goal is to correct life-threatening physiology either concurrently or prior to definitive anatomic correction which can be delayed.
Acute Care Surgery Around the World: Future Perspectives
Increasing specialization and fragmentation of ‘general surgery’ has reduced the role of surgeons to care for patients with acute surgical emergencies. The need for such services, however, has escalated due to the population living to older age with increasingly complex diseases and co-morbidities. Compounding the problem is the mounting number of severely injured patients in the emergency departments which are already filled to capacity by non-emergency patients. Other factors have also contributed to the emergence of the new specialty of ‘acute care surgery’. These include the dissatisfaction of surgeons with trauma as a career in the current era of non-operative management of many traumatic injuries; the loss of traditional general surgery cases to ‘organ-specific practices’ (e.g. colon and rectal surgery, upper GI surgery, endocrines) and highly specialized techniques (minimally invasive surgery, organ transplantation, and robotic surgery). Even nonsurgical specialties, for example interventional radiology and gastrointestinal endoscopy have eroded the modern surgical practice. The time was ripe for the creation of a new specialty, acute care surgery, created and developed by the American Association of Surgery for Trauma (AAST).
Advanced Colonoscopy and Endoluminal Surgery
Philipp Bozzini is cرایگان!
Philipp Bozzini is considered by many the father of endoscopy. Born in Mainz, Germany, in 1773, Bozzini’s goal was to examine the inner cavities of the human body in designing the Lichtleiter, or “light conductor.” He recognized the importance of direct observation in the ability to understand the physiology and function of human organs . With his design, he also foresaw the ability to perform new procedures and to make existing procedures safer by allowing, for instance, the removal of rectal polyps or cervical tumors to be done under direct visualization rather than to depend on luck. The original Lichtleiter consisted of a vase-shaped lantern made of tin and covered with leather . Within this housed the light source, a wax candle, on a spring device designed to keep the ﬂame at a constant height. A concave mirror was placed to project light through an aperture, onto which various tubular specula could be attached. The mirror directed light toward the hollow organ and avoided reﬂection toward the observer’s eye . On the opposite side was another fenestration onto which an eyepiece was attached for the observer . The tubular specula were made of brass or silver and modifed based of the organ they were meant for: urethra, vagina, rectum, and so on . His conductors were straight to avoid deviating from the straight lines on which light rays travel. In order to observe objects at an angle, for instance behind the nasopharynx, he used a mirror to bend the light. He did note, however, that bending the light compromised the clarity of the image
AIDS in Pakistan Bureaucracy, Public Goods and NGOs
Today you give me syرایگان!
Today you give me syringes, tomorrow you might come and handcuﬀ me’, protested Kamal, the Chief Executive Ofcer of Naya Sewaira, the biggest NGO in Pakistan’s HIV/AIDS sector. We were interviewing Kamal whilst sitting in the air-conditioned head ofce of Naya Sewaira in Islamabad, adjacent to the showroom where injecting drug users, their wives and children, dependent upon this NGO’s detoxifcation units, were selling expensive leather handbags and other hand-made products. Tis NGO was about social enterprise rather than charitable service, since its main purpose was to give ex-drug users training in intensive farming techniques for the production of high-yield crops, which it would sell at a proft.
Alzheimer’s disease: synaptic dysfunction and Aβ
Synapse loss is an eرایگان!
Synapse loss is an early and invariant feature of Alzheimer’s disease (AD) and there is a strong correlation between the extent of synapse loss and the severity of dementia. Accordingly, it has been proposed that synapse loss underlies the memory impairment evident in the early phase of AD and that since plasticity is important for neuronal viability, persistent disruption of plasticity may account for the frank cell loss typical of later phases of the disease. Extensive multi-disciplinary research has implicated the amyloid β-protein (Aβ) in the aetiology of AD and here we review the evidence that non-fibrillar soluble forms of Aβ are mediators of synaptic compromise. We also discuss the possible mechanisms of Aβ synaptotoxicity and potential targets for therapeutic intervention.
Analysis of anti –inflammatory active fractions of Tribulus terrestris by high resolution GC-MS
High resolution GC-Mرایگان!
High resolution GC-MS Analysis of anti –inflammatory active fractions of Tribulus terrestris have been studied. The phytoconstituents of the anti –inflammatory active fractions of Tribulus terrestris were investigated using Thermo Scientific TM DFS high resolution GC-MS Thermo fisher scientific Inc. The GC-MS analysis revealed the existence of 25 compounds, some of them with either known antiinflammatory activity or shows another activities strongly related to the inflammation process.