dB In Group Research Articles

Double-Bundle Anterior Cruciate Ligament Reconstruction Using Bone–Patellar Tendon–Bone Allograft

Background: Nonanatomic transtibial single-bundle anterior cruciate ligament reconstruction (SB-ACLR) with a bone–patellar tendon–bone (BPTB) allograft has been used for a long time and has shown the same satisfactory clinical results as an autograft; however, it has not been reported if a double-bundle ACLR (DB-ACLR) could be performed with a BPTB allograft and achieve even better results. Hypothesis: The DB-ACLR with a BPTB allograft is technically feasible and will be superior to the SB technique in restoring better anterior and rotating stability. Study Design: Cohort study; Level of evidence, 2. Methods: The study was performed with 56 patients, and 52 (25 in the DB group and 27 in the SB group) of them were followed up at 2 to 5 years. With an irradiated deep-frozen BPTB allograft, a standard single-incision arthroscopic technique was used, and the graft was fixed with bioabsorbable interference screws on both the femoral and tibial sides. Outcome assessment at final follow-up included International Knee Documentation Committee (IKDC), Tegner, and Lysholm scores; side-to-side difference by conventional KT-2000 arthrometer; total anteroposterior (AP) laxity by the back-pushing KT-2000 arthrometer; pivot shift (0, +, ++); range of motion (ROM); and isokinetic muscle strength evaluation. Results: Mean follow-up was 47.3 ± 11.5 and 58.2 ± 6.6 months for the DB group and SB group, respectively. A statistically significant difference in favor of the DB group was found with the total AP laxity at 30° (P < .05). The overall incidence of pivot shift in the DB group (4% ++) was significantly lower than that in the SB group (26%: 19% + and 7% ++; P = .029). No significant differences were found between the 2 groups in terms of IKDC score, Lysholm score, Tegner score, conventional KT-2000 arthrometer anterior laxity, ROM, and muscle strength. Conclusion: A DB-ACLR with a BPTB allograft is feasible and achieved more satisfactory results than the transtibial SB technique in terms of total AP stability and rotational stability in spite of no significant differences among other clinical parameters.

Health-Related Quality of Life and Direct Costs in Patients With Anterior Cruciate Ligament Injury: Single-Bundle Versus Double-Bundle Reconstruction in a Low-Demand Cohort—A Randomized Trial With 2 Years of Follow-up

To evaluate health-related quality of life (HRQL) in patients undergoing anterior cruciate ligament (ACL) reconstructive surgery by use of 2 procedures and to estimate the direct costs of surgery. We performed a 2-year randomized, prospective intervention study of 2 surgical ACL reconstruction techniques (anatomic single bundle [SB] v double bundle [DB]). Fifty-five consecutive outpatients, with a mean age of 30.88 years, were randomized to SB or DB ACL reconstruction. The Medical Outcomes Study 36-item Short Form Health Survey (SF-36) was used to measure HRQL (primary outcome). ACL injuries were assessed by the International Knee Documentation Committee (IKDC) score (secondary outcome). The use of medical resources and their costs were evaluated. We included 52 patients in the final analyses (23 in the SB group and 29 in the DB group). At baseline, there were no significant differences in study variables. At 2 years of follow-up, there were no significant differences in SF-36 and IKDC scores between groups. However, compared with baseline, the SF-36 physical function, physical role, bodily pain, social function, and emotional role scores were significantly better in the SB group (P < .05), whereas only the physical function dimension score was better in the DB group (P = .047). IKDC scores at 2 years improved significantly in the SB group (P < .001) and DB group (P = .004) compared with baseline. There was a significant correlation between the SF-36 physical function, physical role, and bodily pain dimensions and the IKDC score at 2 years (P < .05). The costs were € 3,251 for the SB group and € 4,172 for the DB group. HRQL and medical outcomes were similar between SB and DB ACL reconstruction techniques, 2 years after surgery. However, the SB technique was more cost-effective.

Exercise Training Prevents Decrease in Luminal Capillary Diameter of Skeletal Muscles in Rats with Type 2 Diabetes

The purpose of this study was to examine whether exercise training can prevent microangiopathy of skeletal muscles in rats with type 2 diabetes and if succinate dehydrogenase (SDH) activity, an indicator of mitochondrial oxidative enzyme activity, is involved in the prevention of microangiopathy. Six-week-old male Goto-Kakizaki (GK) rats and age-matched male Wistar rats (control group (Con)) were used. GK rats were randomly assigned to nonexercise (DB) and exercise (DBEx) groups. The DBEx group was trained on a treadmill 5 times a week for 3 weeks. No significant differences in the capillary-to-fibre ratio or the capillary density were observed between the 3 groups. The luminal capillary diameter of the DB group was significantly lower than that of the Con group, whereas the capillary diameter of the DBEx group was significantly higher than that of the DB group. In addition, SDH activity was significantly higher in the DBEx group than in the Con and DB groups. Microangiopathy of skeletal muscles in type 2 diabetes was correlated with a decrease in the luminal capillary diameter, which was prevented by exercise training. Thus, the mitochondrial oxidative capacity appears to be involved in the overall mechanism by which exercise prevents microangiopathy.

P-172 - Subgroup of adult attention deficit hyperactivity disorder with bipolar disorder patients in remission the effect of disability and quality of life

Bipolar disorder (BD),attention deficit hyperactivity disorder (ADHD), the presence of clinical symptoms is quite often difficult treatment, symptomatology that makes the complex, the sharpness of diagnostic overshadowing, adversely affecting the course of the disease, is an important condition disrupts the quality of life and functionality. In this study, bipolar disorder, attention deficit and hyperactivity disorder by examining the sub-dimensions,to reach conclusions about the relationship has these symptoms,course of illness İUB,socio-demographic characteristics of this situation, to evaluate the relationship between disability and quality of life. In our study,20% of patients favor BD period, were the symptoms of attention deficit and hyperactivity. Hyperactivity is not component where only the size of the group of patients is the lack of attention,21.3% of patients BD comprised of. DHB mean age between the groups, except that a smaller group, gender, marital status, education level, and there was not a statistical difference at the level of significance for comparison of properties. Clinical presentation in the same way as the age of disease onset and exacerbations in patients with DHB group averages low,the average hospitalization than the other two patients were BD.In our study,no significant differences between the groups at the level of deterioration İGDÖ scores were found to be only BD group. Comparisons of quality of life variables,especially the pure DB group more than those in the DHB group was more impaired. Bipolar disorder, attention deficit and hyperactivity are the dimensions of the disease with increasing disability and impair quality of life.

Age as a predictor of residual muscle weakness after anterior cruciate ligament reconstruction

The objective of this study was to reveal the predicting factors for muscle recovery in the lower extremity after anterior cruciate ligament (ACL) reconstruction. One hundred and thirty-five (135) patients who underwent ACL reconstruction using hamstring autograft were evaluated. Exclusion criteria were bilateral ACL injury, chondral treatment and multiple ligament injury. Nonanatomical single-bundle reconstruction (SB) was performed in 79 patients, and anatomical double-bundle reconstruction (DB) was performed in 56 patients. Strength of quadriceps and knee flexion muscles were assessed at 60°/s using a Cybex II dynamometer (Lumex, Ronkonkoma, NY) at 3, 6 and 9months after ACL reconstruction. Anterior tibial translation and pivot shift test were also evaluated. The medical records were reviewed to extract the following information: age, gender, the amount of pre and postoperative KT 1000, technique of reconstruction (SB or DB) and postoperative knee rotation. No significant difference of muscle recovery in the lower extremity was observed at any time point after ACL reconstruction between the SB and DB groups. The DB group showed significantly better postoperative antero-posterior and rotational knee laxity than the SB group. Logistic regression analysis showed significant correlation with only age and muscle recovery. For clinical relevance, there is a risk of muscle recovery delay when ACL reconstruction is performed in elderly patients. Anatomical DB reconstruction resulted in significantly better knee stability, but had no positive effect on muscle recovery. Retrospective study, Level II.

Double-Bundle versus Single-Bundle Anterior Cruciate Ligament Reconstruction

Background One aspect of the debate over the reconstruction of the anterior cruciate ligament is whether it should be carried out with the single-bundle or double-bundle technique. Hypothesis The double-bundle technique results in fewer graft failures than the single-bundle technique in anterior cruciate ligament reconstruction. Study Design Randomized controlled trial; Level of evidence, 1. Methods A total of 153 patients were prospectively randomized into 2 groups of anterior cruciate ligament reconstruction with hamstring autografts using aperture interference screw fixation: single-bundle technique (SB group, n = 78) and double-bundle technique (DB group, n = 75). The evaluation methods were clinical examination, KT-1000 arthrometric measurement, the International Knee Documentation Committee (IKDC) and the Lysholm knee scores, and magnetic resonance imaging (MRI) evaluation. All of the operations were performed by 1 experienced orthopaedic surgeon, and all clinical assessments were made by 2 blinded and independent examiners. A musculoskeletal radiologist blinded to the clinical data made the MRI interpretation. Results There were no differences between the study groups preoperatively. Ninety percent of patients (n = 138) were available at a minimum 2-year follow-up (range, 24-37 months). Eight patients (7 in the SB group and 1 in the DB group) had graft failure during the follow-up and had anterior cruciate ligament revision surgery (P = .04). In addition, 7 patients (5 in the SB group and 2 in the DB group) had an invisible graft on the MRI assessment at the 2-year follow-up. Also, the anteromedial bundle was partially invisible in 2 patients and the posterolateral bundle in 9 patients. Together, the total number of failures and invisible grafts were significantly higher in the SB group (12 patients, 15%) than the DB group (3 patients, 4%) (P = .024). No significant group differences were found in the knee scores or stability evaluations at the follow-up. Conclusion This 2-year randomized trial showed that the revision rate of the anterior cruciate ligament reconstruction was significantly lower with the double-bundle technique than that with the single-bundle technique. However, additional years of follow-up are needed to reveal the long-term results.

Recovery of Chronic Noise Exposure Induced Spatial Learning and Memory Deficits in Young Male Sprague‐Dawley Rats

Noise has always been an important environmental public health issue for mankind. Although reports exist on hippocampal-dependent spatial learning and memory (LM) impairment due to noise, there are only a few studies that have examined the effects of recovery from noise stress on LM impairments. Therefore, the present study investigated the effects of recovery from chronic noise exposure on LM deficits. In this study, the detrimental effects of noise stress on young male rats in the Morris water maze (MWM) were investigated at 1, 10, 20, 30, and 40 days after the discontinuation of chronic noise exposure of 80 dB or 100 dB for 4 h per day, for 30 days. The levels of monoamine neurotransmitters in the hippocampus were also evaluated by HPLC-EC at the end of each behavioral test. Statistical analysis revealed that rats in the noise-treated groups failed to reach the same level of performance as the controls in the MWM. Further, the levels of dopamine (DA), norepinephrine (NE) and 5-hydroxytryptamine (5-HT) were significantly decreased in the hippocampus after noise exposure. However, the reduction in monoamine levels and impaired water maze performance recovered over time, so that by 30th day after cessation of noise exposure the 80 dB group showed no performance difference from the controls, and by 40th day, the 100 dB group also showed no performance difference from the control. Our findings suggest that noise impaired LM in young male rats and reduced monoamine neurotransmitters in the hippocampus. However, the noise-induced water maze deficits recovered over time, and the concurrent restoration of hippocampal monoamine neurotransmitter levels suggest that they are involved in LM impairments.

Exercise ameliorates diabetic cardiomyopathy by inducing beta2‐adrenergic receptors and miR‐133a, and attenuating MMP‐9

To test the hypothesis that exercise ameliorates diabetic cardiomyopathy by inducing beta2-adrenergic receptors (AR) and microRNA-133a (miR-133a), and attenuating matrix metalloproteinase-9 (MMP-9); ten weeks male db/db (a model for T2D)- DB (i) mice were treated with salbutamol (a beta2-AR agonist-200μg/kg/i.p)-DBS (ii), exercised (swimming-1hr/daily)-DBE (iii), and both treated with salbutamol and exercised (DBES) (iv) for ten days. The cardiac function was determined by echocardiography and contractile function of cardiomyocytes. The levels of beta2-adrenergic receptors (AR), miR-133a and MMP-9 were measured by Western blot, RT-PCR and qPCR. The results show decrease in percentage fractional shortening (%FS=~30) in db/db mice. The improvement in contractile function (±dL/dt) of cardiomyocytes was evident from significant decrease in the time (sec) to attain 90% peak height in DBE (0.175±0.004) and DBES (0.168±0.002) as compared to DB (0.178±0.002) cardiomyocytes, and corroborated by calcium consumption ratio during the same duration DBE (19.02±1.09), DBES (24.13±1.69), and DB (15.46±0.80). The beta2-AR and miR-133a were up regulated, and MMP-9 was down regulated in DBS, DBE and DBES heart as compared to DB group. Based on these findings, we conclude that exercise ameliorates cardiac dysfunction in db/db mice by improving beta2-AR response and miR-133a, and attenuating MMP-9.

Evaluation of tibial rotational stability of single-bundle vs. anatomical double-bundle anterior cruciate ligament reconstruction during a high-demand activity — A quasi-randomized trial

The purpose of this study was to compare the tibial rotational stability of anatomical double-bundle anterior cruciate ligament reconstructed knees with single-bundle anterior cruciate ligament reconstructed knees during a high-demand activity. Total of 66 subjects, (22 with double-bundle anterior cruciate ligament reconstruction, 22 with single-bundle anterior cruciate ligament reconstruction, and 22 healthy control individuals) were examined in this study. Using a 9-camera motion analysis system, motion subjects were recorded performing during a drop landing and cutting. Using the point cluster technique, the internal-external tibial rotation of both knees was calculated. The mean maximum range of motion for each knee was evaluated for 3 groups (double-bundle group, single-bundle group, and control group). Clinical assessment, including Tegner score, Lysholm score, and knee arthrometric measurement, revealed restoration of the reconstructed knee stability with no differences between the two anterior cruciate ligament reconstruction groups. The results showed that both groups resulted in tibial rotation values that were significantly smaller than those in the intact legs and those in the healthy controls. There were no significant differences in tibial rotation between the DB group and the SB group. Therefore anatomical double-bundle reconstruction restores normal tibial rotation no more than single-bundle reconstruction during this high-demand dynamic activity. These results suggest a trend towards dynamic overcorrection after the ACL reconstruction.

Wideband coplanar waveguide to edges-even broadside-coupled stripline transition

A wideband transition between a coplanar waveguide (CPW) and an edges-even broadside-coupled stripline (EEBCS) is proposed. The simple transition is composed of a linear tapered line on the top layer and an electromagnetically-coupled Y-shaped stub on the bottom layer. A back-to-back, 50 Ω CPW to 100 Ω EEBCS transition is simulated, fabricated and measured. It is reported that a maximum insertion loss of 2.4 dB, a return loss better than −10 dB and average group delay of about 0.5 ns are obtained from 1.1 to 11.2 GHz for the transition.

ACL reconstruction in sports active people: Transtibial DB technique with ST/G vs. transtibial SB technique with BPTB: Preliminary results

The single-bundle ACL reconstruction ensures good outcomes and it is a well-established and widespread technique. Nevertheless, some patients still present residual pain and instability. Recent studies have showed that the double-bundle technique restores better natural ACL-fitting kinematics. Long-term clinical studies comparing the two surgical techniques are not frequent and there is no instrument to evaluate function and kinematics during the knee rotation in vivo. In this randomised prospective study performed on sportive people, we compare the BPTB single-bundle ACL reconstruction technique, which is the most common surgical technique performed on these patients’ category, with the ACL double-bundle reconstruction technique (DB), in order to evaluate possible differences between the groups. Comparing the two groups, no statistically significant difference regarding the post-operative Lysholm score ( p = 0.368) the Tegner activity scale ( p = 0.519) and the arthrometric evaluation with KT-1000 ( p = 0.74) have been observed. On the contrary, the IKDC evaluation showed a statistically significant difference ( p = 0.004) better results of the DB group. Moreover, as assessed by the Tegner activity scale, only patients of the DB group were able to return to sports at a pre-injury level. Our data suggest that the double bundle ST/G ACL reconstruction technique results into slightly better outcome than the traditional technique of single-bundle BPTB. The verification and quantification of the advantages of this technique is anticipated with future studies focusing to the accurate measurement of knee rotation during different activities.

Serum Cytokine Alteration is Associated With Optic Neuropathy in Human Primary Open Angle Glaucoma

The purpose of this study is to compare human serum levels of TH1 and TH2 cytokines between 2 stages of primary open-angle glaucoma (POAG) and nonglaucomatous controls. Thirty-two patients with primary POAG and 26 normal control subjects were enrolled into this study. The 32 patients with POAG were divided into 2 subgroups according to their mean defect (MD) with MD better than -12 dB and worse than -12 dB on the visual field. Enzyme-linked immunosorbent assay was used to assay for the levels of TH1 cytokines serum soluble interleukin-2 receptor (sIL-2R), interleukin (IL)-2, IL-12p40, IL-12p70, IL-23, tumor necrosis factor (TNF)-alpha, interferon-gamma, and TH2 cytokines IL-4, IL-6 in the peripheral serum. Patients with mild glaucomatous neuropathy exhibited significant elevations in IL-4 (P<0.0001) and IL-6 (P=0.0302) compared with the controls, whereas higher concentrations of IL-4 (P<0.0001) and IL-6 (P=0.0084) were found in patients with severe glaucomatous neuropathy. The level of IL-12p70 was significantly increased in both the MD >/=12 dB (P<0.0001) and MD <12 dB (P<0.0001) groups. A significant decrease in TNF-alpha levels were observed in MD <12 dB group compared with the controls (P=0.0464), and TNF-alpha levels in MD <12 dB group were lower than MD >/=12 dB group (P=0.0328). No significant differences in serum concentrations of IL-2, sIL-2R IL-12p40, IL-23 and interferon-gamma were found between MD <12 dB group, MD >or=12 dB group, and control group. Significant alterations of serum TH1 and TH2 cytokines are associated with glaucoma, suggesting the possibility that abnormal immune environments contribute to the glaucomatous neuropathy of POAG.

Idiotype‐pulsed antigen presenting cells following autologous transplantation for multiple myeloma may be associated with prolonged survival

Vaccines are attractive as consolidation therapy after autologous stem cell transplantation (ASCT) for multiple myeloma (MM). We report the results of a phase II trial of the immunotherapeutic, APC8020 (Mylovenge), given after ASCT for MM. We compared the results with that of other patients with MM who underwent ASCT at Mayo Clinic during the same time period. Twenty-seven patients were enrolled on the trial between July, 1998 and June, 2001, and the outcomes were compared to that of 124 consecutive patients transplanted during the same period, but not enrolled on the trial. The median (range) follow-up for patients still alive from the vaccine trial is 6.5 (2.9-8 years), and 7.1 (6-8 years) in the control group. The median age was 57.4 range (36.1-71.3) in the DB group and 56.4 (range, 30-69) in the trial group. Known prognostic factors including PCLI, B2M, and CRP were comparable between the groups. The median overall survival for the trial patients was 5.3 years (95% CI: 4.0 years-N/A) compared to 3.4 years (95% CI: 2.7-4.6 years) for the DB group (P = 0.02). The median time to progression and progression-free survival for the trial group was similar to the DB group. Although not a controlled trial, the vaccines given after ASCT appear to be associated with improved overall survival compared to historical controls. This approach warrants further investigation to confirm this and define the role of vaccine therapy in myeloma.

생맥산의 식이가 Streptozocin으로 유도된 당뇨 Rat의 혈당과 혈청 성분 함량에 미치는 영향

이가 식이효율(FER), glucose, creatinine, cholesterol, triglycetide, HDL-cholesterol, 동맥경화지수(AI) 등에 미치는 영향을 조사하였다. 식이효율은 정상군이 5.94%로 가장 높았고, 당뇨대조군은 0.58%로 정상군에 비해 현격한 감소를 보였다. DA군과 DB군은 각각 3.65%, 3.38%로 다른 투여군보다 상대적으로 높은 수...

Double-bundle versus single-bundle ACL reconstruction using the horizontal femoral position: a prospective, randomized study

The aim of this study was to evaluate whether anterior cruciate ligament (ACL) reconstruction using the double bundle technique (DB) improves stability in the knee compared with the single bundle technique (SB) with the femoral tunnel in a more horizontal position (2 or 10 o'clock). We conducted a randomized, prospective study. Forty patients were randomized to the DB group (20 patients) and the SB group (20 patients). Four-stranded semitendinosus and gracilis autologous grafts were used in the SB group and in the DB group the conventional four tunnel technique was carried out using the same tendons. The IKDC complete form was used for the preoperative evaluation, and in the follow-up the IKDC subjective knee evaluation form, IKDC current health assessment form and IKDC knee examination form were used. Anteroposterior (AP) laxity was evaluated by standardised and forced radiology in all patients. No significant preoperative between-group differences were found. During the follow-up, no differences were found between groups, except for significant between-group differences (P < 0.05) between the preoperative and postoperative evaluations. The IKDC index also showed significant differences in the 2-year follow-up. Median scores increased from 48 (range 41-54) to 81 (range 75-87) (P = 0.01) in the SB group and from 52 (range 46-58) to 80 (range 72-88) (P = 0.02) in the DB group. There were no significant differences between the groups in terms of functional scores. In conclusion, the 2 and 10 o'clock placements showed no significant differences between SB and DB techniques in the pivot-shift test, manual and radiological anterior posterior laxity and IKDC scores. However, significant between-group differences were found between the preoperative and postoperative evaluations.

Self-equalised pseudo-elliptical filter made of substrate integrated waveguide

A self-equalised pseudo-elliptical filter on the basis of substrate integrated waveguide technology is proposed and demonstrated over the Ka-band range. The extracted-pole technique is used to synthesise a sixth-order filter with non-resonating nodes. Measured results of the filter exhibit a high selectivity and a minimum in-band insertion loss of about 2.0 dB and small inband group delay variation.

Imbalance of RANK, RANKL and OPG expression during tibial fracture repair in diabetic rats

To clarify the mechanisms of altered bone repair in the diabetic state, we investigated RANK, RANKL and OPG expression by immunohistochemistry and RT-PCR in the fracture sites of rats that were either healthy or made diabetic by alloxan. Histomorphometric analysis of the fracture site at 7 days after fracture revealed that diabetic rats (db) have significantly less hard tissue formation at the fracture site, compared to controls. The number of RANK, RANKL and OPG positive cells was decreased in the db group; however, the RANKL/OPG ratio was similar in controls and db at this time. At day 14, numbers of RANKL and OPG positive cells and the mRNA expression for these markers were higher in the control group than in db (P = 0.008). The RANKL/OPG ratio in the db group was greater than in controls. Our results demonstrate an imbalance of RANKL/OPG expression associated with diabetes that may contribute to the delay of fracture repair during the course of diabetes.

Prevalence of hearing impairment in patients with mild cognitive impairment.

The correlation between hearing and cognition is well established in dementia, but not in mild cognitive impairment (MCI).ObjectiveThe aim of the present study was to define the prevalence of hearing impairment in elderly patients with MCI and in controls.MethodsTwenty-nine patients with MCI and 24 control subjects were analyzed. We evaluated memory and hearing impairments through clinical tests, including the Mini Mental Status Examination, Clinical Dementia Rating (CDR) and Hearing Handicap Inventory for the Elderly Screening (HHIE-S). Audiometries were performed in 22 patients with MCI and 19 subjects in a control group.ResultsMCI patients showed more hearing complaints (68.9%) compared to the control group (25%) (p=0.001). No differences in the intensity of hearing complaints, measured by the HHIE-S, were detected. Nonetheless, differences between mean hearing threshold (MCI group=23.4±11.3dB and control group=16.0±10.1dB) (p=0.03) were identified.ConclusionsThere is a significant association between MCI and hearing impairment. Hearing impairment in MCI patients may be a contributory factor to cognitive decline. This may however be related to the same neuropathological process, due to lesions of cortical areas related to hearing. The early diagnosis of hearing impairment in MCI patients may offer a more appropriate approach to this disease.

An Ultra-Wideband (UWB) Bandpass Filter Using Broadside-Coupled Structure and Lumped-Capacitor-Loaded Shunt Stub Resonators

This paper presents an ultra-wideband (UWB) bandpass filter using a combination of broadside-coupled structure and lumped-capacitor-loaded shunt stub resonator. The broadside-coupled microstrip-to-coplanar waveguide structure provides an ultra-wide bandpass filtering operation and keeps a good stopband at lower frequencies from DC at the same time. The lumped-capacitor-loaded shunt stub resonator creates two transmission zeros (attenuation poles which can be located at the outsides of the two bandedges of the UWB bandpass filter to improve the out-band performance by selecting a suitable combination of the length of the shunt stubs and the capacitance of the loaded chip capacitors. The filter was designed based on electromagnetic simulation for broadside-coupled structure, microwave circuit simulation and experiments for determining the transmission zeros. The filter was fabricated on a one-layer dielectric substrate. The measured results demonstrated that the developed UWB bandpass filter has good performance: low insertion loss about 0.46 dB and low group delay about 0.26 ns at the center of the passband and very flat over the whole passband, and less than -10 dB reflection over the passband. The implemented transmission zeros, particularly at the low frequency end, dramatically improved the out-band performance, leading the filter satisfy the FCC's spectrum mask not only for indoor but also for outdoor applications. These poles improved also the skirt performance at both bandedges of the filter. A lowpass filter has been also introduced and integrated with the proposed bandpass filter to have a further improvement of the out-band performance at the high frequency end. The filters integrated with lowpass section exhibit excellent filter performance: almost satisfying the FCC's spectrum mask from DC to 18 GHz. The developed UWB bandpass filter has a compact size of 4 cm x 1.5 cm, or 4.8 cm x 1.5 cm with lowpass section implemented.

Deterring Harassment at Common Law

Green v DB Group Services (UK) Ltd [2006] IRLR 764 (QBD) In Green the employer was held to be liable following acts of harassment committed against the claimant. The employer was both personally at fault (it was aware of the situation and should have intervened) and vicariously liable for the behaviour of its employees. At first glance the decision seems unexceptional. Certainly, in the wake of Waters v Comr of Police [2000] 1 WLR 1607 and Majrowski v Guy's and St Thomas's NHS Trust [2006] IRLR 695, it comes as no surprise that the employer's responsibility to secure a non-hostile working environment should be enforced in this way. However, on closer inspection it becomes apparent that the employer was not held vicariously liable (as in Majrowski itself) for a statutory tort committed by the employee but for common law liabilities. It was assumed (as it had been in the earlier High Court decision in Barlow v Borough of Broxbourne [2003] EWHC 50) that employees owe one another a duty of care not to inflict psychiatric harm by harassment. This assumption does not appear to have been disputed. Indeed the very same assumption was also made in the more recent case of Clark v Chief Constable of Essex ([2006] EWHC 2290) where the employer was held vicariously liable, on the basis of negligence, for the activities of employees participating in bullying. Green, following Barlow, suggests that one then determines whether the duty in question has been breached by asking ‘did the person or persons involved in the victimisation or bullying know, or ought they reasonably to have known, that their conduct might cause the claimant harm … [and] could they, by the exercise of reasonable care, have taken steps which would have avoided that harm’. The imposition of such a duty on an employee may seem wholly apposite given the potential consequences for the victim of acts such as bullying, harassment and victimisation. However, a fundamental difficulty arises because it is not at all clear whether that imposition accords with precedent.