Principles Of Spectrophotometry Research Articles

Comparison of the Friedewald and Vujovic methods with the calculated LDL concentration in a biochemical auto-analyzer.

To compare the concentration of Low-Density Lipoprotein (LDL-c) obtained using the Friedewald formula with those obtained directly with the RAYTO CHEMRAY 120 autoanalyzer. Cross-sectional study. We evaluated outpatients with a medical request for a lipid profile study (total cholesterol, triglycerides, LDL, and HDL). The analyses were carried out in a RAYTO CHEMRAY 120 autoanalyzer under the principle of spectrophotometry. We obtained LDL-c using the Friedewald and Vujovic formulas. We evaluated 199 individuals whose direct LDL concentration averages were measured by the RAYTO CHEMRAY 120 equipment. Those calculated by the Friedewald and Vujovic formulas were 129.97 ± 32.66, 119.28 ± 30.44, and 127.01 ± 32.01, respectively, and in all cases, significant differences (P < 0.001) were observed with the RAYTO analyzer. In both cases a low positive bias was found with the RAYTO analyzer.. The Passing-Bablok and Deming's regressions showed a linear correlation between both methods (Friedewald and Vujovic) with the LDL values obtained with the Rayto autoanalyzer. Our study found that the Friedewald and Vujovic methods are good predictors of LDL cholesterol levels and have a low level of bias. Therefore, they could be used as potential predictors.

Impact of Age and Clinico-Biochemical Parameters on Clinical Severity of SARS-CoV-2 Infection

Introduction: The surge in novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection leading to coronavirus disease-2019 (COVID-19) has overwhelmed the health system. To help health-care workers and policy makers prioritize treatment and to decrease the burden on health systems caused by COVID-19, clinical severity along with various clinico-biochemical parameters was evaluated by designing a cross-sectional study comprising 236 SARS-CoV-2-infected individuals from Kashmir Valley, India. Methods: Briefly, real-time polymerase chain reaction (RT-PCR) was used for the confirmation of SARS-CoV-2 infection. The principles of spectrophotometry and chemiluminescent microparticle immunoassay (CMIA) were employed to estimate the levels of glucose, TSH, and 25-hydroxy vitamin D levels in serum of infected patients. Results: A total of 236 patients infected with SARS-CoV-2 were taken for this cross-sectional study. Patients with COVID-19 had a male predominance (72.9 vs. 27.1%) and a higher prevalence of 25-hydroxy vitamin D deficiency (72.0 vs. 28.0%) with a mean 25-hydroxy vitamin D levels of 24.0 ± 13.9 in ng/mL. We observed a varied clinical spectrum of SARS-CoV-2 infection with 36.4%, 23.7%, and 29.7% patients having mild, moderate, and severe disease, respectively. We observed that severity of SARS-CoV-2 infection was significantly associated with older age group, hypertension, low TSH levels, and 25-hydroxy vitamin D deficiency. Conclusion: We conclude that not only old age but also hypertension and low levels of TSH and 25-hydroxy vitamin D levels could significantly lead to clinical severity of SARS-CoV-2 infection.

Brief descriptions of the principles of prominent methods used to study the penetration of materials into human hair and a review of examples of their use.

Consumers are attracted to the latest fashion trends and different looks. This drives the search for novel hair treatments. Some chemicals present in hair treatment products can penetrate the hair shaft. These materials can either nourish or injure the hair cortex. Different techniques have been used to investigate the mechanism of molecule penetration and the conditions under which penetration occurs. This article reviews the techniques applied for this purpose. Various microscopy techniques are used to capture clear and colourful images to determine the diffusion pathways and the exact location of the molecules under study. However, the laborious sample preparation often leads to sample destruction since cross-sectioning is often required. While various other techniques have been successfully used for investigating the penetration methods, most of these require different amounts of work to be put in for sample preparation and instrumentation. Several spectroscopic techniques have been used to study the penetration of the molecules because of the high levels of accuracy and the quick response time of these techniques. Moreover, the samples are not damaged during the investigation.

Aplikasi Metode Spektrofotometri pada Klasifikasi Gas Karbon Monoksida (CO) dan Uap Bahan Bakar Petrodiesel (C14H30)

Gas classification techniques are often found in several applied fields such as, detection of leak gas in gas cylinders, monitoring the threshold of harmful pollutant gases in the air, health diagnostics, early detection of fire hazards, and others. This requires measurement techniques that are adaptive and robust that can dynamically capture information on changes in vapor or gas compounds contained in free air. This research has been conducted to analyze and identify the types of gas compounds, namely CO and petrodiesel fuel vapor (C14H30). The design of this tool uses the principle of spectrophotometry and the calculation of Backprogation Neural Networks. The working principle is that light radiation in the Light Emitting Diode (LED) series, which has a wavelength range of 385nm to 1720nm, is absorbed to penetrate CO gas or petrodiesel fuel vapor (C14H30) that you want to identify. Light radiation that has passed through the gas / vapor compound was captured by the photodiode sensor. The emission of LED series light radiation produces different wavelength absorption patterns that will be processed by the Backprogation Neural network as an input signal in the identification and learning process. The results of this experiment show the success rate of the Backpropagation neural network in identifying the type of CO gas and petrodiesel fuel vapor (C14H30) is 80%.&#x0D;

Seric Calcium and Magnesium in Normal and Pre Eclamptic Pregnant Women: A Case-Control Study in Kinshasa, D R Congo

Goal: The present study aimed to determine the profile of seric calcium and magnesium in pre-eclamptic and eclamptic pregnant women of Kinshasa province in the Democratic Republic of Congo where preeclampsia is characterized not only by a high incidence, but also by a seasonal variation probably related to nutritional intake. Study Design: This is a case-control study that took place during the period from September 2014 to March 2015 in four quaternary and tertiary maternity hospitals in Kinshasa. A total of 113 healthy pregnant women (controls) and 112 pre-eclamptic and eclamptic pregnant women (cases) were included in this study. Seric calcium and magnesium were measured in all these gravidas by the principle of spectrophotometry with a HUMALYSER Primus semi-automaton. Results: The mean age of those gravidas was 26.8 ± 6.3 years (26.7 vs 26.9, p = 0.11). The majority of these gravidas were primiparous. The mean gestational age in both groups was 31.35 ± 0.9 weeks (32.1 vs 30.6, p = 0.21). The average seric calcium value was 4.47 ± 0.23 mEq /L in healthy pregnant women compared to 3.80 ± 0.71 mEq/l in pre-eclamptics (P 0.001). The mean of seric magnesium was 1.56 ± 0.15 mg/dL in healthy pregnant women compared to 1.20 ± 0.41 mg/dL in pre eclamptics (P 0.001). Seric calcium and magnesium values were low in the pre-eclamptic group and lower in the eclamptic group (P 0.001). Conclusion: This study establishes a relationship between the low concentration of seric calcium and magnesium with pre-eclampsia and eclampsia, which could be one of the determinants of the high prevalence and seasonality of the disease in Kinshasa.

Design of Ubiquitous Pulse Oximetry

In recent years, people have difficulty to breathe a good air quality. It is caused by vehicle emission, household combustion devices, forest fires, and industrial facilities are regular sources of air pollutants. These air pollutants can impair people health and behavior. It means that decreasing oxygen supply can reduce our immune system. The effect of reducing oxygen in our blood cause rapid fatigue, difficulty breathing, muscle pain, eye irritation and even more severe would have a heart attack. Monitoring peoples' health is one of solutions to increase the quality of human life. The pulse oximetry widely used to measure the oxygen level or oxygen saturation (SpO 2 ) in the blood. While it has long been an important tool in clinical practice, pulse oximetry has become a popular medical tool for outside hospital environment use. Pulse oximetery work by the principles of spectrophotometry: the relative absorption of red (absorbed by deoxygenated blood) and infrared (absorbed by oxygenated blood) light of the systolic component of the absorption waveform correlates to arterial blood oxygen saturations. Patients usually take measure using pulse oxymetry in a stationary condition. While pulse oximetry recording a patient's oxygen level, the finger should not move until the recording is completed. The previous research have been evaluated a pulse oximetry in mobile condition. This paper will investigate the relationship between oxygen saturation and light attenuation in the proposed design of the ubiquitous pulse oximetry in mobile condition. This design will help the future development of SpO 2 recording ability while patient in walking condition and give good accuracy as same as off-the-shelf pulse oxymetry.

Cardiology patient page. Screening for critical congenital heart disease in newborns.

We have come a long way in our ability to treat critical congenital heart conditions, which affect about 3 of every 1000 live births and account for 30% of all infant fatalities in the United States annually.1 Prenatal sonograms can often identify structural heart disease; however, the sensitivity of congenital heart disease (CHD) detection is highly variable, depending on operator expertise, gestational age, fetal position, and the type of cardiac defect. As a result, prenatal sonography will miss some patients with critical CHD and is known to miss many newborns with simple CHD. Newborns who might benefit from early treatment can often be identified in their first days of life through pulse oximetry screening—a painless, readily available noninvasive examination that is easy to incorporate into newborn assessments. This noninvasive test measures the percentage of hemoglobin in the blood that is saturated with oxygen and pulse rate. The addition of pulse oximetry to fetal ultrasound and physical examination as a screening tool can reduce the chance of overlooking critical congenital heart disease (CCHD) in newborns.2 Oxygen breathed in through the lungs attaches to the red blood cell protein hemoglobin. The newly oxygenated blood then circulates to the tissues. Arterial hemoglobin saturated with oxygen is bright red, and venous hemoglobin with less oxygen is darker. Pulse oximetry uses the principles of spectrophotometry and …

Diagnostic significance of total creatine kinase and its isoform in tubal ectopic pregnancy

Tubal ectopic pregnancy (tEP) must be diagnosed as early as possible because it is one of the leading causes of pregnancy-related death in the first trimester. The aim of this study was to evaluate the diagnostic value of serum total creatine kinase (CK) and its isoforms in diagnosis of tEP. The study included 32 tEP cases, and gestational age-matched intrauterine (IU) abortion and normal pregnancy cases (n = 31 each). Serum total CK and CK-MB fraction were measured by the principle of spectrophotometry and CK-MM fraction was calculated from the above parameters. Serum β-hCG was measured using chemiluminescent immunoassay. All study parameters were measured at the time of presentation. Serum β-hCG levels were significantly low in patients with both tEP and IU abortion than normal pregnancy. Women with tEP had higher concentrations of total CK, CK-MM and lower concentrations of CK-MB% compared to both gestational age-matched IU pregnancy controls and IU abortion. Receiver-operator characteristic analysis revealed that the optimal cut-off for total CK, CK-MM and CPK-MB% as predictors of ruptured EP were 147 IU/L, 135 IU/L and 10%, respectively, with the former two having higher specificity, and latter high sensitivity. Estimation of CK and its CK isoenzyme fractions can aid in quick and accurate diagnosis of tEP.

The Evolution of Clinical Chemistry as Reflected in Textbooks Published in the United States

On the occasion of the 50th anniversary of the American Association for Clinical Chemistry, Dr. Thomas Annesley, Book Reviews Editor of Clinical Chemistry , felt that a review of clinical chemistry textbooks covering the past three decades would enable the younger generation of clinical chemists to appreciate the profound changes that have taken place in the clinical chemistry laboratory. He also felt that having worked in clinical chemistry laboratories for 40 years, which is tantamount to “being present at the creation”, qualified me for this assignment. While preparing this review, I recognized an interdependence among the practice of clinical chemistry and the contents of textbooks and Clinical Chemistry . As to what comes first, in my slightly biased opinion the Journal has set, and is setting, the pace for textbooks and laboratory practice. I focus on the book of N.W. Tietz, because comparison of the four editions depicts the dramatic changes that occurred in the clinical chemistry laboratory from 1970 to 1993, and on the 1964 book of R.J. Henry, because it was the most comprehensive and informative book of clinical chemistry of its time. Although there are several other important clinical chemistry textbooks, as depicted in Table 1⇓ , they were not reviewed because the changes between the first and last edition do not depict the metamorphosis of the clinical chemistry laboratory from the mid-1960s to the mid-1990s. R.J. Henry published the first comprehensive textbook of clinical chemistry in 1964; it dealt almost exclusively with the analytical aspects of the new, evolving medical laboratory discipline. Its 29 chapters covered principles of spectrophotometry, flame photometry, gasometric techniques, electrophoresis, accuracy, precision, control charts, significant figures (still abused by most authors and journals), and normal values. Analytical methods were described for various proteins and amino acid metabolites found in urine in …

The Use of Erythrosin B in Undergraduate Spectrophotometry Experiments

The CMU chemistry department has met regulatory and waste disposal concerns by using a non-toxic food color in a general chemistry experiment. Erythrosin B was found to be a suitable alternative to Sodium Dichromate when teaching solution preparation and the principles of spectrophotometry. Students weigh a small mass of Erythrosin B and prepare several solutions that are measured in a spectrophotometer. From these a Beer's Law plot is constructed. Finally, concentrations of unknown solutions are determined using the spectrophotometer and the Beer's Law plot.

Induced liquid phase mixing due to bubble motion at low gas velocity

AbstractLiquid phase mixing induced by gas bubbles at low gas velocities was studied experimentally. An experimental technique based on the principle of spectrophotometry was developed and applied in the experimental work. Experimental evidence suggests that the mixing phenomenon can be described as a diffusive process characterized by an effective diffusivity which is found to be a linear function of superficial gas velocity.