Photoplethysmography (PPG) is a non-invasive optical technique that employs variations in light absorption produced by alteration in the blood volume in capillaries at the skin during the cardiac cycle. This study aims to understand factors related to PPG morphology; a hand-elevation, the study has modified blood flow to and from the finger was conducted in the laboratory. It is widely established that the position of the limb relative to the heart has an effect on blood flow in arteries and venous. Peripheral digital pulse wave (DPW) signals were obtained from 15 healthy volunteer participants during hand-elevation, and hand-lowering techniques wherein the right hand was lifted and lowered relative to heart level, while the left hand remained static. The pulse width, time to peak (TTP), the time to the maximum slope (TTMas) were computed from 30sec DPW signals at three positions of the right hand with regard to heart level, i.e. 35 cm above heart level (+35 cm), at the level of the heart (0 cm), and 35 cm below the level of the heart (-35 cm). DPW characteristics were found to alter with hand position. On lowering the hand to -35 cm relative to heart level, DPW width from the middle finger increased by (6%), but lowering the arm decreased the TTP (by 11 %), TTMas (by 18 %). These changes in time-dependent DPW indices may be attributed to changes in hydrostatic pressure and the venoarterial reflex that changes the blood vessels filling from completely filled one at -35 cm due to arterial vasoconstriction and decreased venous return to partially emptied blood vessels due to arterial vasodilatation and increased venous return at +35 cm. It was assumed that these time-dependent morphological DPW indices alterations were controlled by changes in downstream venous resistance rather than arterial or arteriolar, resistance. Keywords: photo plethysmography, hand elevation, vasoconstriction, vasodilation, vascular mechanics
Background: Orthodontic tooth movement is characterized by tissue reactions, which consist of an inflammatory response in periodontal ligament and followed by bone remodeling in the periodontium depending on the forces applied. These processes trigger the secretion of various proteins and enzymes into the saliva.The purpose of this study was to evaluate the activity of alkaline phosphatase (ALP) in saliva during orthodontic tooth movement using different magnitude of continuous orthodontic forces. Materials and Methods: Thirty orthodontic patients (12 males and 18 females) aged 17-23 years with class II division I malocclusion all requiring bilateral maxillary first premolar extractions were randomly divided into three groups according to t
... Show MoreThis paper presents a new approach to discover the effect of depth water for underwater visible light communications (UVLC). The quality of the optical link was investigated with varying water depth under coastal water types. The performance of the UVLC with multiple input–multiple output (MIMO) techniques was examined in terms of bit error rate (BER) and data rate. The theoretical result explains that there is a good performance for UVLC system under coastal water.
The study aimed to identification the effect of brainstorming in linguistically grow of garten child the sample of study is composed from (48)male and female children have been distributed for two groups,one of them is experimental and another is disciplined for every per of garten and pre education,and they have been awarded in a number of variations. For measuring the subordinate variation(linguistically grow)the researcher prepared ascale for this purpose that consist of two parts:the first part the scale of linguistically grow of garten child(4-5 years)and the second part the scale of linguistically grow of pre education child (5-6 years).Consist of every one from (20)shapes of linguistically grow shapes for garten chil
... Show MoreWidely present in the environment, arsenic trioxide has been identified as a genotoxic substance that poses a serious risk to public health. The genotoxic potential of arsenic at low allowable dosage levels is assessed in this study. Four groups of twelve adult rats each were created from the 48 total. Animals in Group I were used as controls Chromosome abnormalities found in bone marrow cells were used to assess the mutagenic potential of arsenic. Hematological parameters were also assessed. At 60 and 90 days, the percentage of microsomal degranulation in the hepatic fraction increased and the amounts of RNA and proteins considerably reduced (P < 0.01) in all three dosages given. was employed in order to assess hematological par
... Show MoreThis paper investigates the issue of surface-type effects on traffic noise in Baghdad. Since the raw materials for both flexible and rigid paving are available from local sources, the decision on selecting the type of paving which depends on the budget of the project and the road's importance and function. Knowing that for high traffic volumes and a high percentage of heavy vehicles, rigid pavement is more suitable compared to flexible pavement. In Baghdad, some highways consist of flexible pavement and others of combined pavement (flexible segments and rigid segments), so the study of the effect of surface type on traffic noise becomes an important matter. This study selected three highways: one with flexible pavement and two with combined
... Show MoreBackground: Preparation of platelet-rich fibrin (PRF) is a simple, low cost and minimally invasive method to obtain a natural concentration of autologous growth factors that is widely used to accelerate soft and hard tissue healing, thus, PRF is used in different fields of medicine. The aim of this study was to evaluate the effect of local application PRF on stability of dental implants. Materials and methods: nineteen healthy patients with adequate alveolar bone with two or more adjacent missing teeth and/or bilaterally symmetric to the midline (split-mouth design) missing teeth participated in this study. Each patient received at least two dental implants (Dentium Co., Korea). After surgical preparation of the implant sockets, the PRF was
... Show MoreLeishmania is auxotroph to folic acid,antifolates drug inhibit the synthesis and conversion of folate derivatives. In this study, cytotoxic effect of methotrexate was investigated on the procyclic promastigotes proliferation of L. donovani. The results showed a significant (p ≥ 0.05) difference in growth of treated groups at high concentrations (1000, 500, 250, 125.5) μM after 24, 48 hrs., while at 72 hrs. significant difference was observed at all concentration. The IC50 values was measurable after 24, 48 and 72 hrs. and it was 174.238, 52.283 and 109.175 μM, respectively. The present study showed the cytotoxic effect of methotrexate on the proliferation of promastigotes of the visceral type of Leishmania.
Laser beam has been widely used to improve the mechanical properties of the metals. It used for cutting, drilling, hardening, welding……etc. The use of Laser beam has many features in accuracy and speeding in work, also in the treatment of metals locally, and in the places that is hard to reach by traditional ways. In this research a surface treatment was done to medium carbon steel (0.4%C) which is common kind of steel that is used in industry. Pulsing Neodymium -YAG Laser has been used and 1.06 micrometer wave length and 5 msec and the distance is about 30 centimeter between the exit area of the Laser beam from the system and the piece that treated . We are going to check the fatigue resistance for samples that is
... Show MoreThe predisposing factors and their effect on the increasing of vulvovaginal Candidiasis have been studied in this research. The result indicated that the highest of infection with vaginal Candidias was in the age of women with age of (21-30years) with vaginal itching and discharge, also the results revealed that the pregnancy was the main predisposing factor. The percentage of the infected pregnant Ladies was 33.7% followed by the women who used the IUCD and OCP 22.1%, those who used steroids 5.2% comparing with control women (without predisposing factors).The results also indicated that the most cases of infection were during the third trimester of pregnancy (where the rate of infedion) was 53.9%.-OCP- Oral Contraceptive Pills-IUCD- Intrr
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