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The paper presents a self-sensing control technique for a special type of multilevel motor drive featuring an Open-end Winding Permanent-Magnet Synchronous Motor fed on one side by a main multilevel inverter (MLI) and on the other side by an auxiliary two-level inverter (TLI). In order to minimize the power losses, the MLI manages the machine active power operating at a low-switching frequency. The TLI instead acts as an active power filter and operates at a higher switching frequency and a lower DC-Bus voltage than the MLI. The current control task is shared between the two inverters, as a predictive action is exerted by the MLI, while a feedback action is accomplished by the TLI. Common sensorless rotor position estimation techniques cannot be straightforwardly applied on such a system, due to the particular drive structure. Therefore, a specific technique has been carried out, able to ensure satisfactory efficiency and control performance in all the operating speed ranges by optimally exploiting the different features of the two inverters. Simulation and experimental results confirm the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

Temperature monitoring is a major issue in induction motor drives, because temperature variations under working conditions may affect the machine lifetime and the control performance as well. The paper presents a technique for on-line monitoring the rotor and stator temperature on field-oriented induction motor drives, based on a new approach to estimate the rotor and stator winding resistances. The proposed approach exploits the injection of small additional current signals to extract the thermal status of the electrical machine, without affecting the normal drive operation. Moreover, it features a low computational effort, does not require other transducers than these already present in a standard field-oriented controlled drive and can be applied on both conventional and sensorless induction motor drives. The stator and rotor temperature estimation can be used either to prevent dangerous overheating and for on-line tuning of the control system. The practical effectiveness of the proposed approach is demonstrated by simulations and experimental tests. [ABSTRACT FROM AUTHOR]

The covid-19 pandemic has increased the economic, social and environmental crisis that Latin American countries are experiencing. Bioconstruction is proposed as a way to redeem, or rescue the planet from its eminent devastation, through the promotion of low-polluting local natural materials and techniques. In contrast, the conventional construction of reinforced concrete or fired partition, generates 39% of the greenhouse effect, as a result of the transfer of materials, their firing or the use of machinery, so it is important to reduce it. The objective of this work is to analyze bioconstruction as a proposal to promote decent habitats, as well as to reduce the emission of polluting gases in Latin American countries. The methodology is based on the analysis of bioconstruction considering indicators such as: its impact or scope, projection or scalability, innovation and budget supported by empirical experience in cases developed in countries such as Bolivia, Peru and Argentina. The results show advantages in the works carried out based on bioconstruction, highlighting the benefits in terms of duration, efficiency, humidity and temperature. It is concluded that bioconstruction represents an opportunity in Latin American countries to face the crisis that prevailed before the appearance of the pandemic, but that has increased due to the arrival of covid-19. [ABSTRACT FROM AUTHOR]

A low input current total harmonic distortion (THD) rectifier is presented, tailored around an open-end winding permanent magnet synchronous generator. Specifically, a six-level converter topology is obtained by connecting the generator stator winding to a three level T-type unidirectional rectifier on one side, and to an auxiliary two-level inverter on the other side. The T-type rectifier manages the entire active power stream and operates at the line frequency in order to minimize the switching power losses. The auxiliary inverter is instead driven by a standard PWM technique, being tasked to sinusoidally shape the input current and to actively balance the voltage across the dc-bus capacitors of the T-type rectifier. Such an inverter, being rated at a lower power and at a lower voltage than the T-type rectifier, can exploit low-cost power mosfets. The proposed topology, featuring a very low input current THD, could well supplement in aircraft, portable or distributed generation applications, modern high-speed permanent magnet synchronous generators featuring a quite small stator impedance. Simulation and experimental results confirm the effectiveness of the proposed configuration. [ABSTRACT FROM AUTHOR]

Multiple-motor fed by multiple-converter systems feature a set of electric motor drives sharing the load through a common mechanical coupling. Such a coupling is exploited in this paper to build up a sensorless field oriented control, based on a quite common back-EMF technique to estimate the rotor flux angular position and an original approach to correct estimation errors. The technique is based on the injection of a suitable, very low frequency, sinusoidal signal on the current reference of one of the motor drives. If the estimated rotor flux position is correct, the drive output torque does not show variations. Differently, a torque ripple is generated at the frequency of the injected signal, whose effects on the system speed are easily compensated by the main speed controller. However, due to the mechanical coupling, an additional component of the reference torque current at the frequency of the injected signal is generated on all the other drives. By minimizing such a component, the estimated rotor flux position can be corrected online. The proposed method can also be exploited to estimate actual values of the stator resistance and of the rotor time constant. [ABSTRACT FROM AUTHOR]

An open-end winding machine configuration and a suitable control strategy for medium-voltage ac motor drives applications are proposed in this paper in order to reduce the distortion of phase voltages in multilevel inverters (MLIs). Differently than standard open-end winding configurations, where two inverters provide active power to both sides of the stator winding, a main MLI supplies in this case the machine on one side, while an auxiliary two-level inverter acts as active power filter on the other side. A high efficiency step modulation manages the MLI, while the auxiliary unit is pulse width modulation (PWM) operated. As the phase current harmonic content is improved, the torque ripple is reduced and the drive efficiency is increased. By exploiting the proposed approach, the apparent switching frequency of the system is that typical of a PWM inverter, although the main unit is operated according to a voltage step modulation strategy. Simulation and experimental results confirm the consistency of the proposed methodology. [ABSTRACT FROM PUBLISHER]

The wide spread use of biological control agents in commercial agriculture is frequently limited by the high cost of the biological control agents. We describe in this paper an entomopathogenic nematode (EPN) “in vivo” mass rearing method, not based on the White trap concept, which is both “low technology” and “low labor”, reducing the cost of producing large quantities of EPN IJ to the level conducive for use in an area-wide biocontrol program. Rearing temperature has a significant impact on the number of EPN IJ produced per host larvae and the IJ viability at any point in time. Emerged IJs remain within a non-aqueous, high humidity environment with improved oxygen access without extra steps or equipment. Depending on storage conditions, IJs remain viable for 7–14 d without extra labor. Our laboratory has used this rearing method to rear more than 100 billion IJ in the past 8 years to support an area wide biological control program. [ABSTRACT FROM AUTHOR]

A strong demand for even more compact and reliable power electronic devices has powered the development of advanced design techniques. A key role is played in these techniques by the reliability assessment, a procedure that estimates the expected lifetime according to given mission profiles. The reliability assessment of a low voltage MOSFET working in avalanche mode is considered in this paper through an experimental approach based on the Coffin–Manson law. Differently from previously proposed techniques, based on a thermodynamic analysis, a direct measurement of the thermal strain over the source aluminum layer is instead exploited. The consistence of the proposed technique is evaluated by comparing estimation of the progressive increment of the on-state resistance with results of endurance tests and estimation obtained from previously presented reliability models. The described technique can be applied to assess the reliability of MOSFETs in applications typical of the automotive field, where they are tasked to power inductive loads in unclamped mode. More in general, the method can be exploited to characterize the front metal of MOSFET devices subjected to power cycling, or short-circuit stress tests. [ABSTRACT FROM AUTHOR]

Some of DC actuators used in home automation, office automation, medical equipment and automotive systems require a position sensor. In low power applications, the introduction of such a transducer remarkably increases the whole system cost, which justifies the development of sensorless position estimation techniques. The well-known AC motor drive sensorless techniques exploiting the fundamental component of the back electromotive force cannot be used on DC motor drives. In addition, the sophisticated approaches based on current or voltage signal injection cannot be used. Therefore, an effective and inexpensive sensorless position estimation technique suitable for DC motors is presented in this paper. This technique exploits the periodic pulses of the armature current caused by commutation. It is based on a simple pulse counting algorithm, suitable for coping with the rather large variability of the pulse frequency and it leads to the realization of a sensorless position control system for low cost, medium performance systems, like those in the field of automotive applications. [ABSTRACT FROM AUTHOR]

Detailed analysis of the inheritance of molecular markers was performed in the oomycete plant pathogen Phytophthora infestans. Linkage analysis in the sexual progeny of two Dutch field isolates (cross 71) resulted in a high-density map containing 508 markers on 13 major and 10 minor linkage groups. The map showed strong clustering of markers, particularly of markers originating from one parent, and dissimilarity between the parental isolates on linkage group III in the vicinity of the mating-type locus, indicating a chromosomal translocation. A second genetic map, constructed by linkage analysis in sexual progeny of two Mexican isolates (cross 68), contained 363 markers and is thus less dense than the cross 71 map. For some linkage groups the two independent linkage maps could be aligned, but sometimes markers appeared to be in a different order, or not linked at all, indicating chromosomal rearrangements between genotypes. Graphical genotyping showed that some progeny contained three copies of a homologous linkage group. This trisomy was found for several linkage groups in both crosses. Together, these analyses suggest a genome with a high degree of flexibility, which may have implications for evolution of new races and resistance development to crop protection agents. [ABSTRACT FROM AUTHOR]

Introduces the industrial applications of sensorless control for permanent-magnet synchronous motor (PMSM) drives. Industry applications of sensorless drives; Features of the sensorless control of PMSM drives; Rotor position detection at standstill; Experimental results.

Capacity loss over time is a critical issue for lithium-ion batteries powering battery electric vehicles (BEVs) because it affects vehicle range and performance. Driving cycles have a major impact on the ageing of these devices because they are subjected to high stresses in certain uses that cause degradation phenomena directly related to vehicle use. Calendar capacity also impacts the battery pack for most of its lifetime with a capacity degradation. The manuscript describes experimental tests on a lithium-ion battery for electric vehicles with up to 10% capacity loss in the WLTP CLASS 3B driving cycle. The lithium-ion battery considered consists of an LMO-NMC cathode and a graphite anode with a capacity of 63 Ah for automotive applications. An internal impedance variation was observed compared to the typical full charge/discharge profile. Incremental capacitance (IC) and differential voltage (DV) analysis were performed in different states of cell health. A lifetime model is described to compute the total capacity loss for cycling and calendar ageing exploiting real data under some different scenarios of vehicle usage. [ABSTRACT FROM AUTHOR]

Background: Retrograde intrarenal surgery (RIRS) using flexible ureterorenoscopes is a cornerstone approach for renal stone removal, yet it carries a significant risk of postoperative urinary tract infection (UTI). With the emergence of single-use ureterorenoscopes, there is growing interest in their potential to mitigate this risk. This study aimed to compare the postoperative infection rates between single-use and multi-use ureterorenoscopes in RIRS procedures and to identify predictors of postoperative UTI. Methods: Data were collected from 112 consecutive patients who underwent RIRS for renal stones between March 2022 and September 2023. Peri-operative variables including age, gender, body mass index (BMI), stone size, stone location, type of ureterorenoscope, Hounsfield Units (HU), pre-operative hydronephrosis, laboratory analysis, and operative time were evaluated. Univariate and multivariate logistic regression analyses were performed to assess the predictors of postoperative UTI. Results: Of the cohort, 77 surgeries (68.7%) utilized multi-use ureterorenoscopes, while 35 (31.3%) utilized single-use devices. Stone diameter, number of stones, type of ureterorenoscope, and operative time were significant predictors of postoperative UTI in the univariate analysis. Multivariable logistic regression showed that operative time (OR, 1.3; 95% CI, 0.55–0.99; p = 0.03) and type of ureterorenoscope (multi-use vs. single-use) (OR, 1.14; 95% CI, 1.08–1.2; p < 0.001) were independent predictors of postoperative UTI. Conclusions: In conclusion, this study highlights that multi-use ureterorenoscopes and prolonged operative time are associated with an increased risk of postoperative UTI in RIRS procedures. Careful pre-operative evaluation and meticulous patient selection are essential to minimize the occurrence of postoperative UTIs and optimize patient outcomes in RIRS for renal stones. [ABSTRACT FROM AUTHOR]

A three-phase multi-level multi-input power converter topology is presented for grid-connected applications. It encompasses a three-phase transformer that is operated on the primary side in an open-end winding configuration. Thus, the primary winding is supplied on one side by a three-phase N-level neutral point clamped inverter and, on the other side, by an auxiliary two-level inverter. A key feature of the proposed approach is that the N-level inverter is able to perform independent management of N − 1 input power sources, thus avoiding the need for additional dc/dc power converters in hybrid multi-source systems. Moreover, it can manage an energy storage system connected to the dc-bus of the two-level inverter. The N-level inverter operates at a low switching frequency and can be equipped with very low on-state voltage drop Insulated-Gate Bipolar Transistor (IGBT) devices, while the auxiliary inverter is instead operated at low voltage according to a conventional high-frequency two-level Pulse Width Modulation (PWM) technique and can be equipped with very low on-state resistance Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) devices. Simulations and experimental results confirm the effectiveness of the proposed approach and its good performance in terms of grid current harmonic content and overall efficiency. [ABSTRACT FROM AUTHOR]

A multi-level open-end winding converter topology for multiple-motor drives is presented featuring a main multi-level inverter processing the power delivered to the motors and an active filter based on an auxiliary two-level inverter. The main inverter operates at the fundamental frequency in order to achieve low switching power losses, while the active filter is Pulse Width Modulation (PWM) operated to suitably shape the motor currents. The proposed configuration features less phase current distortion than conventional multi-level inverters operating at the fundamental frequency, while achieving a higher efficiency compared to PWM multi-level inverters. Experimental results confirm the effectiveness of such a configuration on both multiple motors-single converter and multiple motor-multiple converter drives. [ABSTRACT FROM AUTHOR]

The use of robotic surgery (RS) in urology has grown exponentially in the last decade, but RS training has lagged behind. The launch of new robotic platforms has paved the way for the creation of innovative robotics training systems. The aim of our study is to test the new training system from Hugo™ RAS System–Medtronic. Between July 2020 and September 2022, a total of 44 residents from urology, gynaecology and general surgery at our institution participated in advanced robotic simulation training using the Hugo™ RAS simulator. Information about sex, age, year of residency, hours spent playing video games, laparoscopic or robotic exposure and interest in robotics (90.9% declared an interest in robotics) was collected. The training program involved three robotic exercises, and the residents performed these exercises under the guidance of a robotics tutor. The residents' performance was assessed based on five parameters: timing, range of motion, panoramic view, conflict of instruments and exercise completion. Their performance was evaluated according to an objective Hugo system form and a subjective assessment by the tutor. After completing the training, the residents completed a Likert scale questionnaire to gauge their overall satisfaction. The rate of the residents' improvement in almost all parameters of the three exercises between the first and the last attempts was statistically significant (p < 0.02), indicating significant progress in the residents' robotic surgical skills during the training. The mean overall satisfaction score ± standard deviation (SD) was 9.4 ± 1.2, signifying a high level of satisfaction among the residents with the training program. In conclusion, these findings suggest that the training program utilizing the Hugo™ RAS System is effective in enhancing robotic surgical skills among residents and holds promise for the development of standardized robotics training programs in various surgical specialties. [ABSTRACT FROM AUTHOR]

The article presents information on a study conducted on surgical breast cancer patients who underwent physical rehabilitation program (PRP) to evaluate improvements of shoulder mobility, analgesic effect of PRP, and improvements in quality of life (QoL). The study concluded that postoperative early PRP in breast cancer patients surgically treated with axillary dissection considerably improves the glenohumeral joint mobility, reduces pain, and improves QoL.

In the age of information, new platforms are consulted by patients to acquire consciousness about medical treatments. The aim of this study was to assess the level of understanding and feasibility of video consensus (VC) administration in patients scheduled for radical prostatectomy (RP), comparing it with standard informed consensus (SIC). According to the European Association of Urology Patient Information, we set up a video content for RP that was translated in Italian and implemented with information about possible perioperative and postoperative complications, days of hospitalization etc. From 2021 to 2022, all patients undergoing RP at our institution were prospectively included in this study. Patients received an SIC and after that, a VC about RP. After two consensuses were administered, patients received a preformed Likert 10 scale and STAI questionnaires. On the RP dataset, 276 patients were selected and 552 questionnaires for both SIC and VC were evaluated. Out of these, the median age was 62 years (IQR 60–65). Patients reported a higher overall satisfaction for VC (8.8/10) compared to the traditional informed consent (6.9/10). Therefore, VC may play a role in the future of surgery, improving the consciousness and satisfaction of patients and reducing preoperative anxiety. [ABSTRACT FROM AUTHOR]

Prostate cancer (PCa) surgery has a strong impact on men's social and sexual lives. For this reason, many patients ask for robotic surgery. To assess the rate of lost patients due to the lack of a robotic platform (RPl) at our center, we retrospectively selected 577 patients who underwent prostate biopsy between 2020 and 2021 who were eligible for radical prostatectomy (RP) (ISUP ≥ 2; age ≤ 70 yr). Patients eligible for surgery who decided to be operated received a phone call interview asking the reason for their choice. Overall, 230 patients (31.7%) underwent laparoscopic-assisted radical prostatectomy (LaRP) at our center, while 494 patients (68.3%) were not treated in our hospital. Finally, 347 patients were included: 87 patients (25.1%) underwent radiotherapy; 59 patients (17%) were already under another urologist's care; 113 patients (32.5%) underwent robotic surgery elsewhere; and 88 patients (25.4%) followed the suggestion of friends or relatives based on their surgical experience. Despite no surgical technique for RP having shown superiority in terms of oncological or functional outcomes, patients eligible for PCa treatment decided to be operated on elsewhere because of the lack of an RPl. Our results show how the presence of an RPl may increase the case volume of RP by 49% at our center. [ABSTRACT FROM AUTHOR]

The paper is devoted to the study of a second‐order differential equation of type Sturm‐Liouville with coefficients sign changing, and the existence of one positive solution is obtained by requiring a specific growth of the nonlinearity. In particular, this study is useful in the analysis of the dynamical performance of a class of power converter. [ABSTRACT FROM AUTHOR]

This paper deals with a novel hybrid transformer configuration for MV/LV three-phase distribution systems. The configuration involves a standard distribution transformer with an open-end secondary winding, which is connected to the LV grid and a four-legged inverter with a floating DC bus. Unlike previous hybrid transformers, the proposed configuration eliminates the need for a bidirectional converter and auxiliary transformer windings as well. The fourth leg of the inverter is exploited to manage the neutral line current. The main advantage of the proposed configuration is its ability to provide phase voltage control at the distribution grid edge. This enables the compensation of various grid voltage anomalies such as sags, swells and some kinds of interruptions. The effectiveness of the proposed configuration is demonstrated through simulation and experimental results, highlighting its promising performance in real-world scenarios. [ABSTRACT FROM AUTHOR]

In this paper, an innovative converter topology is presented that allows to improve the performance of electronically commutated motor drives, aimed to equip home appliances. The proposed topology is based on a modified C-dump converter configuration, where the energy recovery stage acts as an active power factor controller (PFC) for offline operation. This is made possible by introducing a new technique to manage the free-wheeling energy that is recovered back to the dc bus by a suitable high frequency (HF) transformer. The proposed approach allows to omit the PFC stage that is included in motor drives devoted to home appliance applications in order to comply with power quality requirements. Moreover, the proposed converter topology features only low side or high side configuration switches, allowing to simplify the design of the drive and easily integrate the power semi-conductors in a single chip exploiting smart power technologies. Simulations and experimental results confirm the validity of the proposed approach. [ABSTRACT FROM AUTHOR]

This paper presents a new technique to detect the slip angular frequency in induction motor drives with indirect field-oriented control (IFOC). Slip frequency is calculated by processing the effects exerted by an additional high-frequency signal on the zero-sequence stator voltage. By measuring such a zero-sequence voltage, it is possible to evaluate the air-gap flux and detect the slip frequency in order to implement an IFOC algorithm. According to the proposed approach, rotor time constant errors are not influent as in conventional field-oriented control schemes, thus, complex tuning or compensation techniques are not required. Simulations and experimental tests are performed to evaluate, the consistency of the proposed approach. [ABSTRACT FROM AUTHOR]

This paper aims to demonstrate that, exploiting the sensorless zero-sequence (SZS) air-gap flux estimation technique, it is possible to realize field-oriented induction motor drives without speed and current sensors, able to operate down to zero speed. According to the SZS technique a zero-sequence stator voltage component is generated as a result of the injection of a suitable high-frequency signal on the stator voltage. By manipulation of such a zero-voltage component, that is unaffected by speed and load changes, it is possible to detect both the amplitude and the angular position of the air-gap flux. In the present paper, it is shown that such a technique allows for the estimation of the motor speed and the phase currents, enabling implementation of a field-oriented control as well as speed and current closed control loops using a simple hardware which, with minor modifications, resembles that of an inexpensive constant Volt/Hertz drive. Experimental tests are shown in order to practically confirm the expected features of the proposed approach. [ABSTRACT FROM AUTHOR]

Although sensorless techniques are among the preferred topics of many researchers around the world, the challenge they represent in terms of finding a robust and effective solution for sensor elimination in ac machine drives has not yet been completely solved. This is especially true for induction motor (IM) drives that still remain the "drive choice" for most of the low- and mediumperformance applications. This paper discusses how standard control methods of IM drives can be improved by adopting a sensorless flux estimation procedure. [ABSTRACT FROM AUTHOR]

Background: To test the clinical activity and toxicity profile of the combination regimen of vinorelbine and cisplatin in a series of patients with carcinoma of the cervix uteri with de novo metastatic disease or recurrent disease after previous therapy. The main aims of the study included analysis of objective response rates, toxicity, and time to progression. Patients and Methods: Forty-two eligible patients were enrolled into the trial and treated with cisplatin 80 mg/m[sup 2] on day 1 and vinorelbine 25 mg/m[sup 2] on day 1 and 8. This regimen was repeated every 21 days upon resolution of toxicity for 3 cycles before response assessment. Enrolled patients had a median age of 53 years, a median ECOG performance status of 1, and mostly a squamous cell histology (86%). Sixteen patients (38%) were treatment-naive since first diagnosed with widespread metastatic disease, 7% had only previous surgery, 31% radiotherapy, and 24% both radiation and surgical therapy. In previously radiated patients, 21% of patients had disease only within the radiation fields, 21% only outside the radiation fields, and 12% both inside and outside the radiotherapy portals. Results: All patients were evaluable for response analysis. A complete response was achieved in 5 patients (12%), and a partial response in 15 cases (36%) for an overall response rate of 48% (95% CL 22–52%). Patients with recurrent disease within the previous radiation field (including those also with disease outside the radiation fields) showed a 28% overall response rate with no complete response, while patients with disease previously untreated with radiotherapy or with tumour deposits only outside of ratiation portals yielded a 57% overall response rate with a 18% complete response rate. Only 1 out of 8 patients with performance status 2 showed a major response (12%). Median time to progression was 5.6 months (range 2.0–14 months). The median overall survival of the whole series was 9.1 months. Hematological toxicity was the most frequent side-effect. Grade 3 vomiting was recorded in 9 patients (21%), and mild mucositis in 14% of patients. Grade 3 neutropenia was observed in 21% of patients, while grade 4 in 12% of cases with neutropenic fever was seen in 4 cases. Sixteen patients (38%) complained of grade 1–2 constipation, while grade 1–2 peripheral neuropathy was seen in 8 patients (19%). Conclusions: The results achieved in this trial suggest that the combination regimen of vinorelbine and cisplatin may be safely given to patients with metastatic and/or recurrent carcinoma of the uterine cervix. This regimen is active at least in terms of objective response rates. Although satisfactory results are still lacking, these results suggest that the vinorelbine-cisplatin regimen is worthy of further studies and may represent the basis for the development of new active regimens.Copyright © 2002 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

This paper describes a new and straightforward approach to estimate the air-gap flux position in induction machines. The proposed scheme is based on the injection of a high-frequency oscillating stator voltage instead of a three-phase high-frequency voltage, thus allowing a reduction in audible noises and torque ripple. The main feature of the proposed approach is that a simple air-gap flux tracking algorithm is developed using the amplitude variation of the high-frequency component of the zero-sequence voltage. Moreover, the zero-sequence voltage is sensed at the output of the inverter rather than at motor terminals. The estimated position is not influenced by load and parameter variation and can be performed at any frequency, including low and zero frequency. An experimental prototype has been implemented showing the performance of the proposed approach. [ABSTRACT FROM AUTHOR]

Voltage wave reflection phenomena along power cables are particularly threatening on ac motor drives equipped with silicon carbide power mosfets due to very short switching times and high switching frequency. Overvoltage suppression resistance inductance capacitance (RLC) networks are usually added but leading to extra cost and a lower efficiency. A completely different overvoltage mitigation approach is presented in this paper exploiting an open-end winding motor configuration. Overvoltage occurring on the terminals of motor phase windings are, in fact, mitigated by simply coordinating the operations of the two inverters; thus, no passive RLC networks are required. The proposed approach is intended as a mean to provide a further valuable feature to open-winding systems at no extra cost, but it can be also valued as an alternative to conventional bridge inverters equipped with overvoltage mitigation devices. [ABSTRACT FROM AUTHOR]

The development and the validation of an averaged-value mathematical model of an asymmetrical hybrid multi-level rectifier is presented in this work. Such a rectifier is composed of a three-level T-type unidirectional rectifier and of a two-level inverter connected to an open-end winding electrical machine. The T-type rectifier, which supplies the load, operates at quite a low switching frequency in order to minimize inverter power losses. The two-level inverter is instead driven by a standard sinusoidal pulse width modulation (SPWM) technique to suitably shape the input current. The two-level inverter also plays a key role in actively balancing the voltage across the DC bus capacitors of the T-type rectifier, making unnecessary additional circuits. Such an asymmetrical structure achieves a higher efficiency compared to conventional PWM multilevel rectifiers, even considering extra power losses due to the auxiliary inverter. In spite of its advantageous features, the asymmetrical hybrid multi-level rectifier topology is a quite complex system, which requires suitable mathematical tools for control and optimization purposes. This paper intends to be a step in this direction by deriving an averaged-value mathematical model of the whole system, which is validated through comparison with other modeling approaches and experimental results. The paper is mainly focused on applications in the field of electrical power generation; however, the converter structure can be also exploited in a variety of grid-connected applications by replacing the generator with a transformer featuring an open-end secondary winding arrangement. [ABSTRACT FROM AUTHOR]

A novel approach of exploiting the stator-temperature-monitoring system to perform sensorless rotor-position estimation is described in this paper. The rotor position is, in fact, estimated by processing the voltages induced in thermistor cablings, which are modified in order to work as search coils (SCs). Using SCs, some typical drawbacks of sensorless position-estimation techniques based on the manipulation of fundamental components of stator voltages and currents, such as those related to inverter non-linearities, stator-resistance voltage drops, magnetic saturation and cross-coupling, can be overcome or mitigated. According to the proposed approach, a rotor-position-tracking technique for synchronous reluctance motor drives is developed independently from motor parameters. Such a sensorless rotor-position-estimation technique can be directly used to build up a sensorless controller or to improve the performance of conventional model based sensorless control systems. Simulations and experimental tests confirm the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

This paper deals with the development and implementation of an on-line technique for the identification of the stator resistance and permanent magnet flux linkage on three-phase, open-end winding, permanent magnet synchronous motor (PMSM) drives. The stator resistance and permanent magnet flux linkage are independently determined by exploiting a special current vector control strategy, which holds one of the phase currents at zero while suitably modifying the other two in order to keep the magnetomotive force unchanged. As will be demonstrated, no additional sensors or special tests are required by the proposed technique; moreover, motor electrical parameters can be on-line estimated in a wide operating range, avoiding any detrimental impact on the torque capability of the PMSM drive. Finally, the electrical machine thermal status can be also estimated from obtained values of the stator resistance and permanent magnet flux linkage. [ABSTRACT FROM AUTHOR]

An electrically assisted internal combustion engine is obtained by combining a conventional engine and one or more electrical motors of considerably smaller size. A key feature of such an innovative vehicle hybridization approach is that the torque generated by electric machines is not transmitted to the wheels. The electric motors are, in fact, intended only to assist the internal combustion engine in low efficiency, low performance, or high polluting working conditions. They however, draw extra power and energy from the battery. This paper presents a tool to evaluate different possible solutions in terms of energy balance, efficiency, battery stress and battery ageing. The method, which is based on suitable mathematical models and specific analysis criteria is also exploited to compare eight different configurations of a C-segment vehicle, pointing out limits and capabilities of traditional 12−14 V systems. [ABSTRACT FROM AUTHOR]

An optimal current control strategy for asymmetrical hybrid multilevel inverters (MLIs) is proposed in this paper enabling their use on motor drives, static synchronous compensators, and photovoltaic and wind generators, where a fast and precise current regulation is required. A key feature of these highly efficient converters is that an ac machine (motor or transformer) operates according to an open-end winding configuration, connected on one side to a main MLI and, on the other side, to an auxiliary two-level inverter (TLI). The first efficiently controls the main power stream operating at a low switching frequency, while the TLI acts as an active power filter, exploiting a conventional high-frequency two-level pulsewidth modulation (PWM) technique. The proposed control scheme optimally exploits the key features of the two inverters by suitably sharing the control task. In fact, a predictive current control is assigned to the MLI, which can be accomplished by low switching frequency operations, while the high switching frequency of the PWM-operated TLI is exploited to accomplish a fast and precise closed-loop current control, processing only a part of the power stream flowing through the system, thus producing low power losses. Simulations and experimental results confirm the consistency of the proposed approach. [ABSTRACT FROM AUTHOR]

Due to their inner structural redundancy, ac multidrive systems (MDSs) can achieve a fault-tolerance capability with minor circuit modifications. However, some additional components are generally required in order to create emergency current paths. According to a recently presented approach, the amount of additional components can be reduced by exploiting healthy drives to support faulty drives. This can be obtained by connecting together the neutral points of motor stator windings and suitably sharing the neutral current of faulty units among some, or all, healthy units. Following such an approach, three current-sharing methodologies for fault-tolerant MDSs are presented in this paper, which are able to cope with single or multiple failures. They are first theoretically introduced and then validated by mean of simulations and experimental test results. [ABSTRACT FROM PUBLISHER]

Ureaplasma urealyticum is an opportunistic pathogen during pregnancy and in newborns. Other clinical problems related to U. urealyticum infections are: no susceptibility to cell wall-active drugs, limits of antibiotic treatment in pregnancy, and spread of antimicrobial resistance. In addition, the results of antimicrobial susceptibility against U. urealyticum from various countries are few and controversial. The antimicrobial susceptibility of U. urealyticum, isolated from cervical swabs and collected from outpatient childbearing-aged women in Italy from 2009 to 2012, was performed against fluoroquinolones, macrolides, streptogramin and tetracyclines, using an available biochemical commercial kit and a specific solid culture medium, to improve the therapeutic management of these pathogenic agents. Ureaplasma urealyticum was detected in 49.4% of samples, but significant bacterial load was revealed in 29.8%. In vitro tetracyclines showed the best activity against U. urealyticum, followed by streptogramin, macrolides, and fluoroquinolones. [ABSTRACT FROM AUTHOR]

Benign lymphoreticulosis (cat scratch disease, CSD) may have a clinical course that varies from the most common lymphadenitis localized in the site of inoculation, preceded by the typical "primary lesion," to a context of severe systemic involvement. Among these uncommon clinical aspects, there is mammarian granulomatous lymphadenitis which may appear as a mastitis or a solitary intraparenchymal mass, giving the impression of a breast tumor. In these cases, intensive clinical, instrumental, and laboratory investigations are necessary to exclude malignancy. Because of its rarity, in equivocal cases, it is reasonable to use surgical excision for accurate histological examination. We report a case of CSD of the breast in a 59-year-old woman, analyzing the clinical, histopathological, and instrumental appearance and also performing a literature review. [ABSTRACT FROM AUTHOR]

Background. Despite the introduction of screening bases intrapartum prophylaxis, Streptococcus agalactiae is still an important etiological agent of perinatal infections. The increasing rate of resistance and the differences in resistance pattern among countries suggest that a program of surveillance at the institutional level is important in determining optimal prophylaxis. In contrast, knowledge on GBS epidemiology in Italy is limited, and no data are available in the Southern region of the country. We sought to determine the occurrence of resistance to macrolides and clindamycin of GBS isolates in pregnant and nonpregnant women. Methods. Between 2005 and 2008, 1346 vaginal and 810 rectovaginal swabs were obtained frompregnant and not-pregnant women. Results. The occurrence of macrolides and clindamycin resistance was 16.5% in 2005 increasing up to 69.9% in 2008. A high percentage of isolates was resistant to tetracycline through all the study period with no statistically significant annual. Conclusions. In our cohort, an increase of in vitro resistance of GBS to macrolides and clindamycin is clearly evident. The discordance with reports from different countries emphasize the crucial role of microbiological methods in setting possible therapeutic strategies. [ABSTRACT FROM AUTHOR]

This paper analyzes different aspects of the maximum-torque-per-ampere (MTPA) vector control of interior permanent-magnet synchronous motors at steady state and transient. Two different implementations are considered: a nonlinear-model-based MTPA profile including saturation and cross-saturation effects and a technique based on the maximization of the motor input power versus stator current. Furthermore, this paper analyzes the torque evolution during a transient under an MTPA control strategy on motors with different characteristics. Useful modifications of the current loop are suggested to improve the drive performance. The effects of the torque transient on the sensorless rotor position estimation are also taken into consideration, in case a sensorless MTPA implementation is required. Experimental results confirm the theoretical analysis, showing the benefits of the new control schemes. [ABSTRACT FROM AUTHOR]

Colon cancer is the second leading cause of cancer death worldwide. Approximately three quarters of patients are diagnosed with disease limited to the bowel wall or surrounding lymph nodes. Over the past decade, significant progress has been made in the treatment of localized colon cancer. The use of adjuvant chemotherapy has improved prognosis in stage III disease, but much work remains to be done in optimizing adjuvant treatment. The FOLFOX4 regimen is now considered standard treatment for stage III disease. Combinations of irinotecan and 5-fluorouracil (5-FU) have not proven to be more effective than 5-FU/folinic acid. In stage II, the value of post-operative treatment remains controversial, but the identification of histopathological and molecular prognostic factors would allow selection of patients who can benefit from adjuvanttreatment. The inclusion of molecular targeted agents in combination regimens with cytotoxins, which have already proven effective in advanced disease, is the main field of development in the most recent protocols of adjuvant therapy. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

In this paper, the rotor position of a synchronous reluctance motor is estimated exploiting the natural saliency of the machine through an addition of a small high-frequency sinusoidal voltage to the stator voltage reference. Due to rotor saliency, a stator voltage component is generated orthogonal to the added signal, whose amplitude depends on the phase displacement between the d-axis and the direction of the injected signal. A robust rotor position tracking can be accomplished by adjusting the direction of the carrier voltage in order to minimize the amplitude of the generated orthogonal voltage. The proposed technique allows zero-speed operation, does not require additional voltage or current sensors, and can easily correct the influence of the armature reaction. Experimental results confirm the validity of the proposed sensorless technique. [ABSTRACT FROM AUTHOR]

Summary: Background: The addition of cyclo-oxygenase-2 (COX-2) inhibitors and prolonged constant infusion (PCI) of gemcitabine to treatment for advanced non-small-cell lung cancer (NSCLC) might improve treatment efficacy. We aimed to assess whether the addition of rofecoxib or PCI gemcitabine could improve overall survival compared with first-line treatment with cisplatin plus gemcitabine given by standard infusion. Methods: Patients with stage IV or IIIb (with supraclavicular nodes or pleural effusion) NSCLC who were under 70 years of age and who had performance status 0 or 1 were eligible for this multicentre, prospective, open-label, randomised phase III trial with 2×2 factorial design. Patients were randomly assigned to one of four treatment groups: group A, gemcitabine 1200 mg/m2 in a 30-min intravenous infusion on days 1 and 8 and intravenous cisplatin 80 mg/m2 on day 1, every 21 days for six cycles; group B, the same treatments as group A plus oral rofecoxib 50 mg/day until disease progression; group C, intravenous PCI gemcitabine 1200 mg/m2 in a 120-min infusion on days 1 and 8 and intravenous cisplatin 80 mg/m2 on day 1, every 21 days for six cycles; group D, the same drugs as group C plus oral rofecoxib 50 mg/day until disease progression. The primary endpoint was overall survival; secondary endpoints were progression-free survival, response rate, quality of life, and toxicity. Analyses were intention-to-treat. This trial is registered on the clinical trials site of the US National Institutes of Health website http://clinicaltrials.gov/ct/show/NCT00385606. Findings: Between Jan 30, 2003, and May 3, 2005, 400 patients were enrolled. Median age was 60 years (range 29–71). PCI gemcitabine did not improve overall survival (median 47 weeks [95% CI 40–55] vs 44 [36–52], with standard gemcitabine infusion, hazard ratio (HR) of death 0·93 [0·74–1·17], p=0·41), progression-free survival, nor any other secondary endpoint. Vomiting and fatigue were significantly worse with PCI gemcitabine. The two rofecoxib groups were closed early (on Oct 1, 2004) due to withdrawal of the drug because of safety issues. With intention-to-treat statistical analyses limited to 240 patients (ie, those randomised before July 1, 2004) who had at least 3 months of treatment, rofecoxib did not prolong overall survival (median 44 weeks [CI 36–55] vs 44 [40–54] without rofecoxib, and HR of death 1·00 [0·75–1·34], p=0·85), or progression-free survival, but did improve response rate (41%vs 26%, p=0·02), global quality of life, physical, emotional and role functioning, fatigue, and sleeping. Rofecoxib significantly increased the incidence of diarrhoea and decreased constipation, fatigue, fever, weight loss, and pain, and analgesic consumption. Severe cardiac ischaemia was more frequent with rofecoxib than without; however, the difference was not statistically significant in the primary analysis (p=0·06) and became significant when patients who were randomised between July 1, 2004, and Sept 30, 2004, were included in the analysis (p=0·03). Interpretation: Neither PCI gemcitabine nor rofecoxib prolonged survival in the patients in this study. Rofecoxib improved response rate and several quality-of-life items, including pain-related items and global quality of life. Further studies with less cardiotoxic COX-2 inhibitors are needed in NSCLC. [Copyright &y& Elsevier]

This paper exploits the interaction between the low-frequency and the high-frequency fields created by signal-injection techniques during sensorless estimation of the air-gap flux position in induction machines. Such an interaction causes new phenomena that can be summarized in a modulation of the machine saturation level and creation of harmonics that contain information about the position of the flux. This paper analyzes the issues related to the presence of additional fields and predicts the resulting harmonic content using three different approaches such as analytical calculations, computer simulation, and finite element analysis. Experimental measurements confirm the conclusions of this paper. [ABSTRACT FROM AUTHOR]

The paper presents a method to compute the air-gap flux position in induction motors at very low including zero-stator frequency. A low-frequency (50 ÷ 100 Hz) sinusoidal stationary signal is added to the normal stator variables to provide the machine with a suitable permanent excitation. Such an additional excitation modulates the saturation level of the magnetic core of the machine according to the angular position of the air-gap flux. As a result, a new zero-sequence stator-voltage component is generated that contains useful information about the position of the air-gap flux unaffected by load variation. Such a zero-sequence voltage can be easily employed to provide a wide bandwidth measurement of the air-gap flux position. A key feature of the proposed approach is that a low-frequency (0 ÷ 5 Hz) signal is demodulated, thus avoiding any drawback featured by previous sensorless techniques operating with high-frequency signal injection. [ABSTRACT FROM AUTHOR]

In this paper, a new approach is presented aimed at improving the power factor of pulsewidth-modulation inverters that equip low-power electric motor drives for household appliances. The key feature of the proposed approach consists of exploiting the dc-bus current as a suitable dither generator by means of a high-frequency transformer. Such a strategy is used to force the diode rectifier to draw current from the mains in those periods when, in conventional systems, the diodes are reverse biased, i.e., when the dc-bus capacitor voltage exceeds the ac input voltage. The proposed method allows for elimination of the power-factor controller (PFC) front end, traditionally used to comply with power quality requirements. In comparison with standard PFCs based on a dc/dc converter, the proposed approach represents a cheaper and more feasible solution, not using additional power devices and control circuits. Simulation and experimental results confirm the consistency of the proposed approach. [ABSTRACT FROM AUTHOR]

A multicenter phase I-II trial was carried out with the aim of identifying the dose-limiting toxicity and the maximum tolerated dose of vinorelbine (VNR) in combination with pegylated liposomal doxorubicin at a dose of 20 mg/m[sup 2] every 15 days in patients with metastatic breast carcinoma. In the phase I part of the trial, VNR was given at a dose of 20 mg/m[sup 2] every 15 days to a group of 3 patients. In absence of unacceptable toxicity, VNR was escalated to 25, 30, and 35 mg/m[sup 2] for subsequent groups of 3 patients, until the dose-limiting toxicity was reached. No case of palmar-plantar erythrodysesthesia was recorded in these patients. Grade 4 neutropenia, grade 3 thrombocytopenia, and grade 3 mucositis were the dose-limiting toxicities recorded in patients treated with VNR 35 mg/m[sup 2] . These side effects caused a substantial decrease in programmed dose intensity. Therefore 30 mg/m[sup 2] was considered the maximum tolerated dose of VNR in combination with pegylated liposomal doxorubicin 20 mg/m[sup 2] , both given every 15 days. These dosages were employed for the treatment of further 18 patients included in phase II of the study. The overall response rate, calculated according to an intention to treat analysis, was 63% (95% CI: 44–80%), with 2 patients achieving a complete response. The median time to progression was 7.0 months or more (range 2–14 months). Median duration of objective responses was 8.4 months or more. The duration of the 2 complete responses was 9 and 14 months, respectively. Median duration of survival was 16.0 months or more (range from 4.0 to ≥24.0). Toxicity was generally mild and easily manageable. Neutropenia and mucositis were the most frequently recorded side effects. A case of palmar-plantar erythrodysesthesia was recorded in phase II of the study. In conclusion, the maximum tolerated dose of VNR in association with pegylated liposomal doxorubicin is 30 mg/m[sup 2] on a bimonthly schedule. Moreover, the combination of VNR and pegylated liposomal doxorubicin is active against metastatic breast carcinoma and is associated with a good toxicity profile. Further studies with this combination regimen are warranted.Copyright © 2002 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

This paper describes a low-power Switched Reluctance motor drive for home appliances featuring close to unity power factor and low cost. The proposed drive includes a compact Power Factor Controller input stage based on a quasiresonant boost topology. The converter structure is suitable for integration and allows one to develop an inexpensive chip implementing all the main functions required by such a drive. Experimental results on a prototype are presented to evaluate the efficiency of the proposed drive. [ABSTRACT FROM AUTHOR]

A technique to improve the performance of grid-connected induction motors by exploiting an auxiliary winding set is proposed in this paper. This auxiliary winding features the same distribution of the main winding, although with a reduced number of turns and it is fed by an inverter a fraction of the power in comparison with the rated size of the induction motor. As shown in the paper, through the auxiliary winding, it is possible to set the machine power factor, increasing the efficiency of the power conversion system and mitigating speed oscillations due to torque disturbances. A mitigation of the grid current peaks due to motor start-up is obtainable. First, the proposed technique is theoretically introduced, then a feasibility assessment is accomplished by simulations. [ABSTRACT FROM AUTHOR]

Piezoelectric energy harvesters (PEHs) are a reduced, but fundamental, source of power for embedded, remote, and no-grid connected electrical systems. Some key limits, such as low power density, poor conversion efficiency, high internal impedance, and AC output, can be partially overcome by matching their internal electrical impedance to that of the applied resistance load. However, the applied resistance load can vary significantly in time, since it depends on the vibration frequency and the working temperature. Hence, a real-time tracking of the applied impedance load should be done to always harvest the maximum energy from the PEH. This paper faces the above problem by presenting an active control able to track and follow in time the optimal working point of a PEH. It exploits a non-conventional AC–DC converter, which integrates a single-stage DC–DC Zeta converter and a full-bridge active rectifier, controlled by a dedicated algorithm based on pulse-width modulation (PWM) with maximum power point tracking (MPPT). A prototype of the proposed converter, based on discrete components, was created and experimentally tested by applying a sudden variation of the resistance load, aimed to emulate a change in the excitation frequency from 30 to 70 Hz and a change in the operating temperature from 25 to 50 °C. Results showed the effectiveness of the proposed approach, which allowed to match the optimal load after 0.38 s for a ΔR of 47 kΩ and after 0.15 s for a ΔR of 18 kΩ. [ABSTRACT FROM AUTHOR]