Ultra-high sensitive cancerous cells detection and sensing capabilities of photonic biosensor.

The ultra-high sensitive cancer cell detection capabilities of one-dimensional photonic crystal with defect have been theoretically examined in this work. The simulations of the work have been carried out with MATLAB programming and transfer matrix method. The performance of the proposed biosensor loaded separately with samples containing different cancer cells has been studied by changing the period number, defect layer thickness, and incident angle corresponding to s polarized light only to identify the parameters under which the proposed design becomes ultra-sensitive. The working principle of the proposed biosensor is to sense the minute change in the refractive index of the analytes containing different cancer cells of human. This sensing is done shifting the respective defect mode inside photonic band gap of the structure from one position to other near by position due to change in the refractive index of sample under consideration. Our structure under optimum conditions yields maximum shifting in the position of defect mode from 1538 to 1648 nm corresponding to the samples containing normal and Glioblastoma cells of refractive indices 1.350 and 1.4470 respectively which results a ultra-high sensitivity of 4270.525928 nm/RIU.

MATLAB simulation based study on poliovirus sensing through one-dimensional photonic crystal with defect.

The present work, theoretically examined the poliovirus sensor model composed of one-dimensional photonic crystal with defect. The transfer matrix method with the help of MATLAB software has been used to detect poliovirus present in the water sample. The main objective of the present work is to design an efficient sensor by identifying the minute variation in the refractive index of water sample due to change in the poliovirus concentration present in the sample. The alternate layers of aluminum nitride and gallium nitride has been taken to realize Bragg reflector having defect layer of air at center of the Bragg reflector. The effect of change in thickness of defect layer region, period number and incident angle corresponding to transverse electric wave has been examined to optimize the structure which correspond maximum performance of the proposed poliovirus sensing structure. The maximum performance of the structure has been obtained with optimum value of defect layer thickness 1200 nm, period number 10 and incident angle 40°. Under optimum condition maximum sensitivity of 1189.65517 nm/RIU has been obtained when the structure is loaded with waters sample of poliovirus concentration C = 0.005 g/ml whereas figure of merit, quality factor, signal to noise ratio, dynamic range, limit of detection and resolution values become 2618.28446 per RIU, 3102.06475, 2.27791, 2090.99500, 1.91E-05 and 0.24656 respectively.

Externally tunable multichannel filtering applications of organic material based 1D magnetic cold-plasma photonic crystals.

In the present research work, we employed the transfer matrix method (TMM) in addition to MATLAB software to examine the transmission properties of various organic-based one-dimensional (1D) magnetic cold-plasma photonic crystals (MCPPhCs). The proposed structures were found to be made up of periodic layers of organic materials and magnetic cold-plasma (MCP) at normal incidence. An external magnetic field (B) polarized in right-hand (RH) and left-hand (LH) configurations was applied on 1D MCPPhCs. In this study, four organic materials, namely pentane, hexane, heptane, and octane, were chosen to design four 1D photonic crystals (PCs), named as PC1 (pentane-MCP), PC2 (hexane-MCP), PC3 (heptane-MCP), and PC4 (octane-MCP). Our results indicated that the central frequency of the resonant peaks of unit transmission inside the photonic band-gap (PBG) of the respective organic PCs could be tuned towards the higher or lower frequency side by applying B polarized in RH and LH configurations, respectively. We also studied the effect of the period number N to produce closely spaced N-1 transmission channels of unit transmission inside the PBG of all four organic PCs. By increasing the period number N we could increase the number of transmission channels inside the PBG as per our desire. These multiple resonant peaks of unit transmission inside PBG could be easily modulated inside the PBG to accommodate new frequencies by applying B polarized in either RH or LH configurations, respectively. Moreover, our results showed that under the RH configuration, increasing B resulted in a shifting of the resonant peak towards the higher frequency side with a reduction in its full width half maximum (FWHM), whereas the findings were the opposite in the case of increasing B under the LH configuration. These findings may be beneficial for designing externally tuneable organic chemical sensors in the microwave frequency region.

Study on a one-dimensional defective photonic crystal suitable for organic compound sensing applications.

Organic-compound-based sensors have important applications, such as applications in geothermal power stations, the shoe industry, the extraction of vegetable oil, azeotropic calibration and medical science. Herein, a 1D photonic crystal (PC) with a defect has been used to develop a photonic-technology-based organic compound sensor with optimum performance. The structure of the proposed organic compound sensor consists of a water cavity sandwiched between two symmetric sub-PCs, which are composed of alternate layers of SiO2 and ZnO. The proposed air/(SiO2/ZnO)5/cavity/(SiO2/ZnO)5/glass structure with the optimized structural parameters achieves a quality factor that varies between a minimum value of 4968.2 and a maximum value of 6418.5. The FOM and sensitivity values of the proposed sensing design are on the order of 102 and 103, respectively. The LOD value of the proposed sensor is on the order of 10-5, which is very low, as is always expected for chemical sensing designs. Thus, the simple design and excellent performance make our design highly efficient and suitable for sensing applications in the industrial and biomedical fields.

Therapeutic amnioinfusion for intrapartum fetal distress using a pediatric feeding tube.

OBJECTIVE: To evaluate the role of therapeutic amnioinfusion using a pediatric feeding tube in cases of intrapartum fetal distress. METHODS: A randomized clinical trial including 438 women admitted in labor at Assiut University Hospital with nonreassuring fetal heart rate tracing. Using sealed opaque envelopes, the women were randomized to 2 groups. In the amnioinfusion group they underwent transcervical amnioinfusion (1000 mL of warmed sterile saline solution) in addition to conventional treatment. In the control group they received conventional treatment only. The primary outcome was cesarean section rate for fetal distress. The secondary outcomes were neonatal and maternal complications. RESULTS: The amnioinfusion group showed a significant reduction in the rate of cesarean section for fetal distress (relative risk [RR], 0.7; 95% confidence interval [CI], 0.6-0.83), and a 30% reduction in abnormal fetal heart rate patterns (RR, 0.7; 95% CI, 0.6-0.83). Significantly fewer newborns had Apgar scores less than 7 at 1 and 5 min in the amnioinfusion group than in the control group (RR, 0.38; 95% CI, 0.26-0.55 and RR, 0.31; 95% CI, 0.15-0.64, respectively). Significantly fewer newborns had meconium below the vocal cords in the amnioinfusion group than in the control group (RR, 0.36; 95% CI, 0.13-0.97). Moreover, 14 newborns in the amnioinfusion group needed admission to the intensive care unit vs. 31 newborns in the control group. There were no significant differences between the 2 groups regarding the incidence rates of uterine hypertonus and maternal temperature higher than 38 degrees C. CONCLUSION: Therapeutic amnioinfusion is a simple and effective intervention that reduces the rates of cesarean section for intrapartum nonreassuring fetal heart tracing. In under-resourced settings, it can be performed using inexpensive catheters.

Development of modified release diltiazem HCl tablets using composite index to identify optimal formulation.

This article reports the preparation of tartaric acid treated ispaghula husk powder for the development of modified release tablets of diltiazem HCl by adopting direct compression technique and a 32 full factorial design. The modified ispaghula husk powder showed superior swelling and gelling as compared to untreated powder. Addition of compaction augmenting agent such as dicalcium phosphate was found to be essential for obtaining tablets with adequate crushing strength. In order to improve the crushing strength of diltiazem HCl tablets, to modulate drug release pattern, and to obtain similarity of dissolution profiles in distilled water and simulated gastric fluid (pH 1.2), modified guar gum was used along with modified ispaghula husk powder and tartaric acid. A novel composite index, which considers a positive or a negative deviation from an ideal value, was calculated considering percentage drug release in 60, 300, and 540 min as dependent variables for the selection of a most appropriate batch. Polynomial equation and contour plots are presented. The concept of similarity factor (f2) was used to prove similarity of dissolution in water and simulated gastric fluid (pH 1.2).

Prophylactic transcervical amnioinfusion in laboring women with oligohydramnios.

OBJECTIVES: Evaluation of prophylactic intrapartum amnioinfusion in women with oligohydramnios. METHODS: Assiut University Hospital during the period from February 2000 to September 2001, 160 laboring women with oligohydramnios [amniotic fluid index (AFI)

Studies in release behavior of diltiazem HCl from matrix tablets containing (hydroxypropyl)methyl cellulose and xanthan gum.

(Hydroxypropyl)methyl cellulose and xanthan gum were used as hydrophilic matrixing agents for preparing modified release tablets of diltiazem HCl. The amount of (Hydroxypropyl)methyl cellulose and xanthan gum exhibited significant effect on drug release from the tablets prepared by direct compression technique. Xanthan gum showed a higher ability to retard the drug release than (Hydroxypropyl)methyl cellulose. A 2(2) + 1 factorial design was adopted to study the effect of amount of (Hydroxypropyl)methyl cellulose and xanthan gum on percent drug released in first hour (Y60) and the time required for 90% drug dissolution (t90). A response surface plot is generated for investigating the effect of the independent variables on t90. The tablets containing 90 mg diltiazem HCl, 45 mg (Hydroxypropyl)methyl cellulose and 45 mg xanthan gum showed drug release upto 12 h. The value of similarity factor, f2, for the selected batch was found to be 85.1 when the dissolution study was carried out in water or simulated gastric fluid, indicating pH independent drug dissolution. The selected batch also showed a comparable release profile with a market product (f2 = 60.2). Linear relationship was observed between percent drug released and degree of swelling. The kinetics of the drug release fitted well to the Hixson-Crowell equation. It can be concluded that by using a suitable blend of (Hydroxypropyl)methyl cellulose and xanthan gum desired modified drug release can be achieved.

Ovarioscopy, a technique to determine the nature of cystic ovarian tumors.

STUDY OBJECTIVE: To test the value of ovarioscopy as an additional step in the diagnostic work-up of probably benign cystic ovarian tumors before laparoscopic intervention, and to compare its diagnostic accuracy with that of transvaginal ultrasonography (TVUS) and tumor markers. DESIGN: Cross-sectional study (Canadian Task Force classification II-2). SETTING: Gynecologic endoscopy unit at a university hospital. PATIENTS: Sixty-eight women with unilateral or bilateral ovarian cystic swellings without clinical, sonographic, or laparoscopic suspicion of malignancy. INTERVENTION: Preoperatively, TVUS and tumor markers were estimated. Intraoperative endocystic ovarioscopic visualization ovarioscopy and ovarioscopy-guided biopsy were done before laparoscopy. MEASUREMENTS AND MAIN RESULTS: Ovarioscopy had the highest specificity for detecting benign ovarian cysts (98%) compared with (72.6%) and (72%) for tumor markers and TVUS, respectively. Its positive predictive value was 50% compared with 5% and 6% for tumor markers and TVUS, respectively. Its findings agreed with the histopathologic diagnosis in 39 patients (57%, p = 0.000, k = 0.85). CONCLUSION: Ovarioscopy is a simple, rapid maneuver that should precede laparoscopic ovarian cystectomy. It is superior to tumor markers and TVUS for predicting the benign nature of ovarian cysts.

Modulation of drug release rate of diltiazem-HCl from hydrogel matrices of succinic acid-treated ispaghula husk.

The feasibility of using succinic acid-treated ispaghula husk in matrix-based tablets of diltiazem-HCl was investigated. The sample prepared using 4:1 weight ratio of ispaghula husk to succinic acid showed improved swelling and gelling. A 3(2) factorial design was employed to investigate the effect of amount of succinic acid-treated ispaghula husk and dicalcium phosphate (DCP) on the percentage of the drug dissolved in 60, 300, and 480 min from the compressed tablets. The results of multiple linear regression analysis revealed that the significance of the amount of succinic acid-treated ispaghula husk was greater in magnitude than that of the amount of DCP in controlling the drug release. Acceptable batches were identified from a contour plot with constraints on the percentage drug released at the three sampling times. A mathematical model was also evolved to describe the entire dissolution profile. The results of F-test revealed that the Higuchi model fits well to the in vitro dissolution data. The tablets showed considerable radial and axial swelling in distilled water. Succinic acid-treated ispaghula husk can be used as an economical hydrophilic matrixing agent.

Formulation design and optimization of modified-release microspheres of diclofenac sodium.

The present study deals with the preparation of microspheres of diclofenac sodium using cross-linked poly(vinyl alcohol) (PVA). A central composite design consisting of a two-level full factorial design superimposed on a star design was employed for developing the microspheres. The PVA to the drug ratio X1 and amount of glutaral-dehyde cross-linking agent X2 were chosen as the independent variables. The time required for 50% drug dissolution t50 in phosphate buffer (pH 7.2) was selected as the dependent variable. An optimum polynomial equation was generated for the prediction of the response variable t50. Based on the results of multiple linear regression analysis and F statistics, it may be concluded that sustained action can be obtained when X1 and X2 are kept at high levels. The X1X2 interaction was found to be statistically significant. A response surface plot is presented to show the effects of X1 and X2 on t50. The drug release pattern fit the Higuchi model well. A model was validated for accurate prediction of the drug dissolution profile with constraints on the percentage drug release in the first, fifth, and seventh hours. The data of a selected batch were subjected to an optimization study, and an optimal formulation was fabricated. Good agreement was observed between the predicted and the observed dissolution profiles of the optimal formulation.

Formulation optimization of controlled release diclofenac sodium microspheres using factorial design.

Diclofenac sodium is an ideal candidate for incorporation in a controlled release device to diminish its adverse effects after oral administration. Microspheres were prepared by using sodium alginate as a polymer and CaCl2 as a cross-linking agent. In this investigation, 3(3) full factorial design was used to investigate the joint influence of the three variables: the stirring speed (X1), concentration of CaCl2 (X2) and % of heavy liquid paraffin in a blend of heavy and light liquid paraffin in the dispersion medium (X3) on the time of 80% drug dissolution (t80). Potential variables such as concentration of sodium alginate and drug: sodium alginate ratio were kept constant in the experimental design. A statistical model with significant interaction terms is derived to predict t80. The results of multiple linear regression analysis and F-statistics revealed that for obtaining controlled drug release, the microspheres should be prepared using relatively lower stirring speed, higher concentration of CaCl2 and higher percentage of heavy liquid paraffin in the dispersion medium. The X1X2 and X2X3 interactions were found to be statistically significant in nature. A response surface plot is presented to show the effects of X1, X2 and X3 on t80. The drug was released by diffusion of anomalous type. A model was validated for accurate prediction of drug release profile. Acceptable batches were identified in the experimental design with constraints on percentage drug released in 1, 6 and 8 h.