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.     

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.     

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.

Hemodynamic effects of amlodipine and benazeprilat in spontaneously hypertensive rats

We wished to assess the hemodynamic effects of administration of the combination of the calcium channel blocking agent amlodipine and the angiotensin-converting enzyme (ACE) inhibitor benazeprilat in conscious spontaneously hypertensive rats (SHR). In SHR previously instrumented for measurement of mean arterial blood pressure (MAP) and heart rate (HR), intravenous (i.v.) injection of amlodipine (0.25-4 mg/kg) produced dose-dependent decreases in blood pressure (BP). Administration of benazeprilat (0.1-10 mg/kg i.v.) decreased arterial MAP, and benazeprilat (10 mg/kg) effectively blocked the effects of exogenously administered angiotensin I (AI). In animals surgically prepared for measurement of BP, HR, and hindquarter, renal, and mesenteric blood flows, administration (i.v.) of the combination of amlodipine (0.5 mg/kg) with benazeprilat (10 mg/kg) evoked a decrease in BP that was greater than that elicited by monotherapy. The tachycardic response observed after administration of the combination was no different from that observed after monotherapy with amlodipine. Simultaneous administration of amlodipine and benazeprilat produced reductions in vascular resistance in the hindquarter, renal and mesenteric beds that were greater than the responses evoked by injection of either agent. The major finding of these studies was that dual therapy with amlodipine and benazeprilat produced an additive hypotensive effect in conscious SHR. Regional vasodilation accompanied the large degree of hypotension evoked by the combination.     

Impact of Ultra Wide Band emission on WiMAX systems at 2.5 and 3.5 GHz

In this work, results of an analytical analysis to assess the effect of Ultra Wide Band (UWB) emissions on the Worldwide Interoperability for Microwave Access system (WiMAX) are presented. The WiMAX range is evaluated with and without the UWB interference. Free space propagation model is used to calculate the UWB signal power that interferes with WiMAX systems. It is shown that, for the case of single UWB transmitter, WiMAX system can easily tolerate UWB interference when the UWB EIRP is ?83 dBm/MHz or less for a distance between the UWB transmitter and the WiMAX receiver of 1 m or higher at 3.5 GHz frequency in order to have only 5% range reduction. To make this possible, multi band UWB should not transmit in the first and the second bands. This will have a detrimental effect on UWB technology. For 2.5 GHz WiMAX, the range reduction will be 5% when the UWB EIRP is ?87 dBm/MHz.     

The application of SEAT values for predicting how compliant seats with backrests influence vibration discomfort

The extent to which a seat can provide useful attenuation of vehicle vibration depends on three factors: the characteristics of the vehicle motion, the vibration transmissibility of the seat, and the sensitivity of the body to vibration. The ‘seat effective amplitude transmissibility’ (i.e., SEAT value) reflects how these three factors vary with the frequency and the direction of vibration so as to predict the vibration isolation efficiency of a seat. The SEAT value is mostly used to select seat cushions or seat suspensions based on the transmission of vertical vibration to the principal supporting surface of a seat. This study investigated the accuracy of SEAT values in predicting how seats with backrests influence the discomfort caused by multiple-input vibration. Twelve male subjects participated in a four-part experiment to determine equivalent comfort contours, the relative discomfort, the location of discomfort, and seat transmissibility with three foam seats and a rigid reference seat at 14 frequencies of vibration in the range 1–20 Hz at magnitudes of vibration from 0.2 to 1.6 ms⁻² r.m.s. The ‘measured seat dynamic discomfort’ (MSDD) was calculated for each foam seat from the ratio of the vibration acceleration required to cause similar discomfort with the foam seat and with the rigid reference seat. Using the frequency weightings in current standards, the SEAT values of each seat were calculated from the ratio of overall ride values with the foam seat to the overall ride values with the rigid reference seat, and compared to the corresponding MSDD at each frequency. The SEAT values provided good predictions of how the foam seats increased vibration discomfort at frequencies around the 4-Hz resonance but reduced vibration discomfort at frequencies greater than about 6.3 Hz, with discrepancies explained by a known limitation of the frequency weightings.     

W-CDMA Uplink Capacity and Interference Statistics of Rural Highways Cross-Shaped Microcells

The capacity and the interference statistics of the sectors of the cross-shaped W-CDMA cell are studied using an analytical approach. A model of 49 cells is used to analyse the uplink, which limits the capacity. The cells are assumed to exist in rural zones. The capacity and the interference statistics of the microcell are studied for different sector ranges and different antenna sidelobe levels.     

WCDMA Uplink Capacity and Interference Statistics of Highways Shaped Microcells with Imperfect Power Control and Finite Transmitted Power

The capacity and the interference statistics (mean and variance) of the sectors of a Cigar-, Tee-, and Cross-shaped WCDMA microcells are studied. Models of 5, 7, and 9 microcells are used to analyze the uplink capacity of the cigar-, Tee-, and cross-shaped W-CDMA microcell, respectively. The capacity and the interference statistics of the microcell are studied for different sector range and antenna side lobe levels. It is shown that the highest sector capacity is obtained when the microcell is cigar-shaped. For a cross-shaped microcell, the sector capacity is the lowest. Also it is shown that the uplink sector capacity will be very high if synchronous WCDMA is used in the uplink. To get the quasi maximum capacity, the sector range should be (0.6 – 1) km and the side lobe level of the directive antenna used in each sector should be – 15 dBc or lower.     

The vibration of inclined backrests: perception and discomfort of vibration applied parallel to the back in the z-axis of the body

This study determined how backrest inclination and the frequency of vibration influence the perception and discomfort of vibration applied parallel to the back (vertical vibration when sitting upright, horizontal vibration when recumbent). Subjects experienced backrest vibration at frequencies in the range 2.5 to 25 Hz at vibration magnitudes up to 24 dB above threshold. Absolute thresholds, equivalent comfort contours, and the principal locations for feeling vibration were determined with four backrest inclinations: 0° (upright), 30°, 60° and 90° (recumbent). With all backrest inclinations, acceleration thresholds and equivalent comfort contours were similar and increased with increasing frequency at 6 dB per octave (i.e. velocity constant). It is concluded that backrest inclination has little effect on the frequency dependence of thresholds and equivalent comfort contours for vibration applied along the back, and that the W (d) frequency weighting in current standards is appropriate for evaluating z-axis vibration of the back at all backrest inclinations. STATEMENT OF RELEVANCE: To minimise the vibration discomfort of seated people, it is necessary to understand how discomfort varies with backrest inclination. It is concluded that the vibration on backrests can be measured using a pad between the backrest and the back, so that it reclines with the backrest, and the measured vibration evaluated without correcting for the backrest inclination.