Biocatalytic production of lactose ester catalysed by mica-based immobilised lipase

Enzyme immobilisation technology is an effective means to improve sugar ester production through the employment of biocatalysts. In the present study, immobilisation of Candida rugosa (CRL) lipase onto amino-activated mica is performed via covalent bonding (namely Amino-CRL) and the cross-linking of lipases into nano-reactors through physical adsorption (namely NER-CRL). Free and immobilised lipases were tested for their esterification activities. Specific activities for Amino-CRL and NER-CRL increased by 2.4 and 2.6-fold, respectively, upon immobilisation. Extending this work, immobilised lipases have novel capabilities in the synthesis of sugar esters. The optimised conditions for sugar fatty acid ester syntheses are 48 h at 2:1 of molar ratio of lactose sugar to capric acid at 55 °C. Furthermore, a high operational stability with half-lives of over 13 and 10 runs was achieved for NER-CRL and Amino-CRL, respectively, indicating the efficiency of the immobilisation process.     

WCDMA Uplink Capacity of a Long Tunnel Cigar-shaped Microcells for Underground Train Service

In this paper, the capacity and the interference statistics of the sectors of the cigar-shaped WCDMA microcells are studied using the hybrid model of propagation. A model of nine microcells in a metro tunnel is used to analyze the uplink capacity and the interference statistics. The capacity and the interference statistics of the microcells in metro tunnels are studied in this work for different propagation parameters, antenna side lobe levels, sector ranges and bends losses.

Lambertian reflectance and linear subspaces

We prove that the set of all Lambertian reflectance functions (the mapping from surface normals to intensities) obtained with arbitrary distant light sources lies close to a 9D linear subspace. This implies that, in general, the set of images of a convex Lambertian object obtained under a wide variety of lighting conditions can be approximated accurately by a low-dimensional linear subspace, explaining prior empirical results. We also provide a simple analytic characterization of this linear space. We obtain these results by representing lighting using spherical harmonics and describing the effects of Lambertian materials as the analog of a convolution. These results allow us to construct algorithms for object recognition based on linear methods as well as algorithms that use convex optimization to enforce nonnegative lighting functions. We also show a simple way to enforce nonnegative lighting when the images of an object lie near a 4D linear space. We apply these algorithms to perform face recognition by finding the 3D model that best matches a 2D query image.     

Copper Ion Extraction by a Mixture of Fatty Hydroxamic Acids Synthesized from Commercial Palm Olein

Abstract

A mixture of fatty hydroxamic acids (FHA), synthesized from a commercial palm olein, was evaluated as an extractant for extraction of copper ion from aqueous media. The content of hydroxamic acid groups in the FHA, analyzed by elemental analysis, was 3.52 mmol/g. Copper extraction from aqueous media was studied by solvent extraction technique using octanol as an organic phase. The extraction of copper ion was through the formation of 1∶2 (Cu(II)∶FHA) complex, pH dependent and not affected by the presence of a large amount of Co(II), Ni(II), Cd(II) and Zn(II) ions.     

Neurotrophic ulcer after extra-capsular cataract operation.

Although neurotrophic ulcers due to herpes zoster are seldom, there may be challenging cases. Especially neurotrophic corneal ulcers after cataract operations should arise the possibility of a previous herpes zoster attack and the treatment plan should be prepared accordingly. This case highlights the importance of thorough evaluation of cataract patients in order not to miss a previous diagnosis of herpes.     

A simple capillary column GC method for analysis of palm oil-based polyol esters

A reliable, simultaneous analysis of palm oil polyol esters using capillary column GC is described. The polyol esters were esterified from palm oil methyl esters (POME) and palm kernel oil methyl esters (PKOME) with trimethylolpropane [2-ethyl-2-(hydroxymethyl)-1,3-propanediol; TMP] to produce the biodegradable base oil for lubricant production. Analysis was performed using a high-temperature capillary column, SGE HT5 operated at a temperature gradient of 6°C/min starting from 80 to 340°C. Before injection, the sample was derivatized with N,O-bis (trimethylsilyl)trifluoroacetamide in ethyl acetate at 40°C for at least 10 min. This procedure provides a complete separation of reaction products: TMP, methyl esters, monoesters (ME), diesters (DE), and triesters (TE). As expected, the ME from palm kernel oil was resolved into five major peaks, DE into seven peaks, and TE into 10 peaks. Since no standard was available for this sample, the identities of the peaks were established by a secondary standard that was derived from pure methyl esters. This GC method has made possible the simultaneous determination of reaction product compositions in order to assess the extent of reaction.     

Recent advances in the pharmacotherapy of epilepsy

The therapeutic options for the treatment of epilepsy have expanded during the 1990s. Since 1993, four novel agents (felbamate, gabapentin, lamotrigine, and topiramate) have been approved by the US Food and Drug Administration, primarily for adjunctive treatment of partial seizures. In addition, a water-soluble pro-drug of phenytoin, fosphenytoin, and a sustained-release preparation of carbamazepine have been introduced. The novel anticonvulsants represent a potential improvement for patients whose seizures are incompletely controlled or who experience significant adverse effects with older anticonvulsants. Felbamate, lamotrigine, and topiramate appear to have a broad spectrum of action in seizure control, but felbamate use is limited by the potential for serious adverse effects. Gabapentin, lamotrigine, and topiramate are all well tolerated. Gabapentin has no known drug interactions, whereas lamotrigine and topiramate have limited interactions compared with older agents. The sustained-release preparation of carbamazepine may decrease the incidence of adverse effects and increase patient compliance. Fosphenytoin offers a safer method for intravenous administration of phenytoin and the added flexibility of intramuscular administration. Taken together, these recent advances in treatment may bring about improved efficacy and decreased adverse effects for many patients with epilepsy.     

Effect of marination and smoking on lipid and fatty acid composition of thornback ray (Raja clavata) and spiny dogfish (Squalis acanthias)

The effects of different processing methods (marinated and smoked) on proximate compositions and fatty acids of thornback ray (Raja clavata) and spiny dogfish (Squalis acanthias) were investigated. Total lipid content was 3.39% in thornback ray and 5.90% in spiny dogfish. The lipids of raw fish consisted mainly of polyunsaturated fatty acids in thornback ray and saturated fatty acid in spiny dogfish. The n?3/n?6 ratio of thornback ray (3.78) was higher compared to spiny dogfish (2.87). After processing, water content decreased significantly while crude protein, lipid, and ash contents increased in both fishes. In general, processing techniques significantly (p?<?0.05) affected fatty acid fractions; in both species, SFA content increased, MUFA and PUFA content decreased. In addition, after processing n?3/n?6 ratios increased although total n?3 and n?6 contents decreased. The results indicated that heat treatment and acidic medium during processing had considerable affects on the proximate and fatty acid composition of the final products. Marinated and smoked products prepared from both fish species offer a balanced fatty acid composition for human nutrition. In terms of fresh and processed products, while the spiny dogfish appears to have a higher PUFA content, the thornback ray is a richer source of EPA?+?DHA.     

Entrance surface dose and image quality: comparison of adult chest and abdominal X-ray examinations in general practitioner clinics, public and private hospitals in Malaysia

This study was undertaken to compare the entrance surface dose(ESD) and image quality of adult chest and abdominal X-ray examinationsconducted at general practitioner (GP) clinics, and public andprivate hospitals in Malaysia. The surveyed facilities wererandomly selected within a given category (28 GP clinics, 20public hospitals and 15 private hospitals). Only departmentalX-ray units were involved in the survey. Chest examinationswere done at all facilities, while only hospitals performedabdominal examinations. This study used the x-ray attenuationphantoms and protocols developed for the Nationwide Evaluationof X-ray Trends (NEXT) survey program in the United States.The ESD was calculated from measurements of exposure and clinicalgeometry. An image quality test tool was used to evaluate thelow-contrast detectability and high-contrast detail performanceunder typical clinical conditions. The median ESD value forthe adult chest X-ray examination was the highest (0.25 mGy)at GP clinics, followed by private hospitals (0.22 mGy) andpublic hospitals (0.17 mGy). The median ESD for the adult abdominalX-ray examination at public hospitals (3.35 mGy) was higherthan that for private hospitals (2.81 mGy). Results of imagequality assessment for the chest X-ray examination show thatall facility types have a similar median spatial resolutionand low-contrast detectability. For the abdominal X-ray examination,public hospitals have a similar median spatial resolution butlarger low-contrast detectability compared with private hospitals.The results of this survey clearly show that there is room forfurther improvement in performing chest and abdominal X-rayexaminations in Malaysia.     

Uplink multiservice capacity and interference statistics of WCDMA macrocells with antenna diversity reception in a multipath fading environment

We generalize the interference modeling method developed by Romero-Jerez et al. to include the effect of the number of Rake fingers, uplink orthogonality factor, number of receiving antennas and the cell radius on the cell uplink capacity. With this model, the capacity of the system for voice only users, data users only and mixed services is obtained. It is noticed that increasing the cell radius from 400 to 800 m reduces the uplink capacity for voice and data services. It is shown that the synchronous WCDMA will increase the uplink capacity by 16.9%. For the nonfading case, the uplink capacity is 12.5% higher than the uplink capacity with a fading channel.