Search Results (38)

The traditional Chinese medicinal herb Gynura segetum is increasingly recognized for its hepatotoxic potential, primarily attributed to its pyrrolizidine alkaloid (PA) content. PAs are a leading cause of herb-induced liver injury (HILI) in China and are strongly linked to hepatic sinusoidal obstruction syndrome (HSOS). This review systematically summarizes the pathogenesis, diagnostic advancements, and therapeutic strategies for PA-induced HSOS. Molecular mechanisms of PA metabolism are detailed, encompassing cytochrome P450-mediated bioactivation and the subsequent formation of pyrrole-protein adducts, which trigger sinusoidal endothelial cell injury and hepatocyte apoptosis. Advances in diagnostic criteria, including the Nanjing Criteria and the Roussel Uclaf Causality Assessment Method (RUCAM)-integrated Drum Tower Severity Scoring System, are discussed. Furthermore, emerging biomarkers, such as circulating microRNAs and pyrrole-protein adducts, are examined. Imaging modalities, such as contrast-enhanced computed tomography (CT) and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) magnetic resonance imaging (MRI), have evolved from descriptive tools into quantitative and prognostic instruments. Therapeutic approaches have evolved from supportive care to precision interventions, including anticoagulation, transjugular intrahepatic portosystemic shunt (TIPS), and autophagy-modulating agents. A comprehensive literature review, utilizing databases such as PubMed and Web of Science, was conducted to summarize progress since the introduction of the “Nanjing Guidelines”. Ultimately, this review underscores the critical need for integrated diagnostic and therapeutic frameworks, alongside enhanced public awareness and regulatory oversight, to effectively mitigate PA-related liver injury. Full article

Backgrounds/Objectives: Trabeculectomy is the gold standard for glaucoma drainage surgery, but it is associated with a risk of sight-threatening complications. The PreserFlo MicroShunt (PF) is a less invasive alternative that aims to reduce complications and simplify post-operative care. This study aimed to compare the effectiveness and safety of PF to trabeculectomy in the management of glaucoma. Methods: This was a retrospective cohort analysis of 95 eyes (48 PF, 47 trabeculectomy) from a single-center private practice in Brisbane, Australia. Data were collected from November 2017 to January 2024. Primary outcomes included intraocular pressure (IOP) and the number of medications. Secondary outcomes included best-corrected visual acuity (BCVA) and complications. Inverse probability of treatment weighting (IPTW) was applied to baseline covariates, and weighted regression and Cox proportional hazards models were then used to estimate treatment effects. Results: The two groups had comparable patient characteristics, although the PF group was older with worse visual field mean deviation. At 12 months, both procedures significantly reduced IOP and medications; however, differences were not statistically significant between groups (2.9 mmHg; 95%CI: −2.0, 7.9; p = 0.303, and 0.4; 95%CI: −0.13, 0.96; p = 0.138, respectively). The estimated probabilities of qualified success were comparable (74.9% PF vs. 72.5% trabeculectomy). Intra-operative stenting in PF eyes eliminated early post-operative hypotony. The incidence of open surgical revision in the PF group vs. the trabeculectomy group was 14.6% vs. 2.1% (p = 0.059, respectively). PF was associated with faster post-operative inflammation resolution (hazard ratio: 6.3; 95%CI: 2.8, 14.5; p < 0.001). Conclusions: Both PF and trabeculectomy are effective for glaucoma management. PF is a less invasive procedure with a lower rate of early hypotony when stented. Trabeculectomy has a tendency for lower IOP reduction and less requirement for open revision, although this did not reach statistical significance. This highlights the need for longer-term studies and improved techniques, such as more effective anti-fibrotic strategies. Full article

The aim of this retrospective clinical pilot study is to evaluate multiparametric ultrasound liver parenchyma assessments in the diagnosis of Osler’s disease, and to detect micro-shunts using SRCEUS with quantifications at the capillary level. Material/Method: All examinations were performed by an experienced examiner with a multi-frequency probe on a high-resolution matrix ultrasound device (SC 7-1U), convex probe (Mindray A 20), and were stored digitally in the PACS system. Vascular ultrasound was performed using colour-coded Doppler ultrasound (CCDS) and ultrasound microangiography (UMA). The recent M-Ref tool was utilised for the purpose of liver tissue characterisation, encompassing the domains of shear wave elastography, fat evaluation, and viscosity. Dynamic CEUS, HiFR CEUS, and SR CEUS were performed after the intravenous bolus injection of 1–2.4 mL of ultrasound contrast agent (SonoVue^®). Measurements of SR CEUS capillary changes were performed independently by PACS-stored digital cine loops up to 5 s. Results: In the context of angiomas or haemangiomas, the initial contrast enhancement of echogenic or almost echogenic foci within 25 s without late wash-out was observed in 5/10 cases. In the evaluation of microvasculature, the presence of capsule-proximal shunts in Osler’s disease was observed, resulting in the identification of increased numbers of dilated capillaries within both peripheral and central shunts. In the control group, general liver tissue changes (20 cases) were observed in instances of inflammation (3/20 cases), peripherally in 4/20 cases with micro-shunts in altered parenchyma. In the context of multiparametric ultrasound, 16 out of 30 cases exhibited elevated fibrosis values, with a maximum recorded as high as 1.7 m/s, and in 13 out of 30 cases, there was an increase in fat values up to 0.65 dB/cm/MHz, indicative of moderate steatosis. Additionally, in seven cases, there was an increase in viscosity values up to 2.7 Pa·s, suggesting reactive changes. Conclusions: Recent advancements in medical imaging technology, specifically SR CEUS contrast ultrasound imaging, have led to the development of novel diagnostic tools that facilitate the evaluation of tissue and haemodynamic changes, in addition to capillary alterations, associated with Osler’s disease. Full article

Background: Glaucoma is the leading cause of irreversible blindness around the world and is characterized as a group of irreversible optic neuropathies with multiple risk factors such as age, race/ethnicity, sex, and intraocular pressure (IOP), amongst many others that play a role in disease etiology. However, IOP is the only modifiable risk factor, with higher IOP often causing increased damage to the optic nerve, resulting in the vast majority of medical and surgical treatments aiming to reduce IOP. There are a number of interventions available to treat glaucoma including micro-invasive glaucoma surgery (MIGS), whose usage has drastically increased due to its safety and efficacy. Studies also highlight the IOP-reducing effect of cataract surgery, which is the most common procedure performed globally. However, other, more targeted therapies and surgeries have been shown to have a more significant effect on IOP reduction. The objective of this study is to compare the IOP and medication reduction between cataract surgery (CS), MIGS, and MIGS and cataract surgery (MACS) clinical trials. Methods: This analysis consisted of publicly available data on CS, MIGS, and MACS clinical trials from 2005 to 2017 using ClinicalTrials.gov. Data reporting and synthesis adhered to PRISMA guidelines. MIGS interventions studied in this analysis include iStent^®, CyPass^® Micro-Stent, Ex-PRESS^®, Hydrus^®, PRESERFLO^™ MicroShunt, and XEN^® Gel Stent. The main variables of interest are the mean IOP and mean number of glaucoma medications used. The primary outcomes were the baseline, post-procedure, and reduction in IOP and glaucoma medication use. Cohorts were further subdivided by the follow-up period (6, 12, and 24 months), as well as their medicated or unmedicated status for pre-op IOP measurement. PROSPERO CRD42025102892. Results: A total of 21 trials were included in this review, comprising 3330 clinical trial participants: 7 CS trials (N = 570), 13 MIGS trials (N = 1577), and 9 MACS trials (N = 1183). All interventions studied resulted in a decrease in both the IOP and medication usage with varying degrees. At 12 months, the wash-out baseline IOP reduction (mmHg) was 6.9 (27.5%) for CS, 8.8 (34.0%) for MIGS, and 8.2 (32.6%) for MACS. The medication reduction was 0.8 (56.1%) following CS, 1.0 (39.5%) for MIGS, and 1.3 (86.4%) for MACS. At 24 months, the wash-out baseline IOP reduction was 6.3 (25.1%) for CS, 8.4 (33.1%) for MIGS, and 7.6 (30.1%) for MACS. At 24 months, the medication reduction was 0.9 (58.3%) for CS, 1.5 (79.8%) for MIGS, and 1.3 (86.1%) for MACS. Conclusions: The results indicate that CS, MIGS, and MACS all result in a decrease in the IOP and glaucoma medications; however, MIGS and MACS outperform CS in IOP and medication reduction. Adopting MIGS and MACS for patients with ocular hypertension or mild-to-moderate glaucoma will help improve patient outcomes through reducing the IOP and medication burden. Given that glaucoma affects certain populations to a greater degree, future research analyzing racial representation is critical in ensuring the appropriate applicability of clinical trial results toward diverse populations. Full article

Background/Objectives: Early postoperative hypotony and complications like choroidal detachment can occur after Preserflo MicroShunt (MS) implantation in patients with pseudoexfoliation glaucoma (PEXG). To prevent these risks, outflow from the microshunt tube can be reduced by implementing a nylon stent. This study aims to evaluate the impact of intraluminal stenting of the MS during the first four months after surgery. Methods: This retrospective study of 43 eyes investigated the incidence of intraocular hypotony in PEXG patients undergoing MS implantation with (n = 23) or without (n = 20) intraluminal stenting using a 10.0 nylon suture. The follow-up period was four months after surgery. Results: Our results demonstrated that intraluminal stenting significantly reduced the incidence of postoperative complications related to hypotony. Notably, no cases of choroidal detachment occurred in the nylon-stenting group (nsMS) compared to 30% (6 eyes) in the MS-only group (p = 0.0064). The hypotony rates between the nsMS (21.74%, 5 eyes) and the MS-only group (40%, 8 eyes) did not significantly differ (p = 0.3184). Both groups experienced significant reductions in intraocular pressure (p < 0.001) and a decrease in the number of antiglaucomatous medications (p < 0.001) up to four months after surgery. Conclusions: The use of an intraluminal stent (10.0 nylon suture) during MS implantation may be a promising strategy to reduce the risk of hypotony-related complications, particularly choroidal detachment, in patients with PEXG. Full article

Background/Objectives: This work aims to clarify whether the subtenon use of the sodium hyaluronate product Healaflow in filtrating surgery with PreserFlo MicroShunt positively influences the early postoperative course in terms of control of intraocular pressure, hypotony, and needling rate. Methods: A retrospective, randomized controlled, interventional, single-center trial was performed at the Ludwig Maximilians-University Munich from January 2024 to July 2024. Only patients with primary open angle glaucoma (POAG) were included. In all patients, a complete ophthalmological examination including best corrected visual acuity (BCVA), automated refraction, and Goldman tonometry was performed at 2 days, 1–4 and 5–8 weeks, and 3–4 and 5–6 months after surgery. Healaflow was injected underneath the tenon during filtrating surgery with PreserFlo MicroShunt in addition to mitomycin C (MMC). The Healaflow group was compared to a control group with POAG patients in which Healaflow was not used during surgery with PreserFlo MicroShunt and MMC. Results: A total of 45 eyes of 45 patients were included, with 20 eyes in the Healaflow group and 25 eyes in the control group. In both groups, a significant reduction in IOP and medication could be observed: complete surgical success (IOP ≥ 6 mm Hg and ≤17 mm Hg, without surgical complications or complete loss of vision) was reached in 88% of patients in the Healaflow group at the last follow-up. In 95% of patients in the control group, complete success could be observed. The success rates did not significantly differ between the two groups (p = 0.568). Hypotony rates were 35% in the Healaflow and 12% in the control group after two days (p = 0.083); the rates equalized after 1–4 weeks (p = 1). Needling rates were comparable between both groups (25% versus 20%, p = 0.731). Conclusions: PreserFlo MicroShunt implantation with MMC was equally effective in terms of reduction in IOP and medication in both scenarios with additional or without the use of Healaflow. Postoperative hypotony and needling rates did not significantly differ between the two groups. The additional effects of Healaflow on anti-scarring and maintaining space are likely too minimal to cause significant differences in IOP or medication when already treated with MMC. Full article

Objectives: This study evaluated the clinical preferences of glaucoma specialists regarding glaucoma surgery and postoperative management in Japan in 2024. Methods: A survey about clinical practice preferences regarding glaucoma surgery and postoperative care was administered among 50 glaucoma specialists who were councilors in the Japan Glaucoma Society. Results: Minimally invasive glaucoma surgery (MIGS) plus phacoemulsification was the most preferred procedure for nonoperated mild to moderate cases of primary open-angle glaucoma (POAG) (94.6%) and normal tension glaucoma (NTG) (67.3%) associated with cataract. Microhook surgery was the most preferred among the MIGS procedures. Meanwhile, PreserFlo MicroShunt (PMS) surgery is emerging as a popular option for cases of POAG and NTG, especially in advanced-stage pseudophakic eyes that underwent prior corneal incision phacoemulsification (40.1%). Long-tube shunt surgeries were predominantly preferred for POAG after two failed trabeculectomies (69.4%) and for neovascular glaucoma with prior vitrectomy after a failed trabeculectomy (73.0%). Among long-tube shunt surgeries, the Ahmed glaucoma valve (AGV) was preferred over the Baerveldt glaucoma implant. Trabeculectomy required the most frequent follow-up visits within the first postoperative year, whereas PMS and long-tube shunt surgeries required comparatively fewer follow-up visits. Overall, MIGS involved less frequent follow-up visits versus filtering surgeries. Conclusions: MIGS is currently the procedure of choice for primary glaucoma surgery in Japan. Among glaucoma specialists of the Japan Glaucoma Society, PMS surgery is becoming popular for cases of POAG and NTG. Refractory glaucoma is commonly treated with long-tube shunt surgeries, especially the AGV. Full article

Background: The aim of this study was to evaluate the effects of Preserflo implantation on endothelial cell density (ECD), corneal thickness, intraocular pressure (IOP), and the use of antiglaucoma medications over a 12-month follow-up period. Methods: A total of 53 eyes from 53 patients undergoing Preserflo implantation were included in this prospective study. ECD, corneal thickness, IOP, and the number of antiglaucoma medications were measured at baseline, 3 months, and 12 months postoperatively. Statistical analysis was performed using paired t-tests and Wilcoxon signed-rank tests for non-normally distributed data. Results: There was no significant reduction in ECD at 3 months (p = 0.695) or 12 months (p = 0.229) compared to baseline. However, a significant reduction in corneal thickness was observed at 3 months (p = 0.008), with no significant change at 12 months (p = 0.118). A significant reduction in IOP was noted at both 3 months (from a preoperative median of 23.5 mmHg to 11.5 mmHg, p < 0.001) and 12 months (from 23.5 mmHg to 13.0 mmHg, p < 0.001). Additionally, there was a significant decrease in the use of antiglaucoma medications, from a preoperative median of 3.0 medication classes to 0.0 classes at both 3 months (p < 0.001) and 12 months (p < 0.001). Conclusions: Preserflo implantation resulted in a significant reduction in IOP and the need for antiglaucoma medications, with no significant impact on endothelial cell density and corneal thickness after 12 months. These findings suggest that Preserflo implantation is an effective procedure for IOP control and medication reduction, with favorable outcome for corneal health after one year. Full article

Background: The PreserFlo™ MicroShunt (PFMS) is a bleb-forming device considered to be less invasive than traditional glaucoma surgery such as trabeculectomy. This study evaluates the 1-year success rates as well as safety profile of PFMS in patients having high intraocular pressure (IOP) and/or glaucoma refractory to drop therapy with a history of prior intravitreal dexamethasone therapy. Methods: A total of 16 eyes after PFMS implantation due to elevated IOP after intravitreal dexamethasone implant (DEX-I) administration were included in this retrospective cohort study. Success rates and secondary outcomes were evaluated. Results: Qualified and complete success rates at 12 months, respectively, were 14/16 and 12/16 eyes for criterion A, 13/16 and 11/16 eyes for B, 13/16 and 11/16 eyes for C, and 6/16 and 6/16 eyes for D. The overall mean (range) preoperative IOP decreased from 27 (16–38) mmHg to 13 (10–17) mmHg at 12 months. BCVA was not significantly different up to 12 months (p = 0.63). The preoperative mean (range) number of medications decreased from 3.56 (2–4) to 0.31 (0–3) at 12 months. One eye underwent needling twice, and two eyes were revised surgically. One patient needed replacement of the PFMS. There were no hypotony-related complications. Conclusions: The PFMS is an effective surgical option for patients with steroid-induced IOP elevation. It demonstrates satisfactory short-term success rates, a reduced need for pressure-lowering eye drops, an excellent safety profile with minimal postoperative care, and a low complication rate. Additional interventions such as needling or revisions were infrequently necessary. However, PFMS may not be the ideal choice for cases requiring a low target pressure (≤12 mmHg). Full article

High-performance acoustic resonators based on single-crystalline piezoelectric thin films have great potential in wireless communication applications. This paper presents the modeling, fabrication, and characterization of laterally excited bulk resonators (XBARs) utilizing the suspended ultra-thin (~420 nm) LiTaO₃ (LT, with 42° YX-cut) film. The finite element analysis (FEA) was performed to model the LT-based XBARs precisely and to gain further insight into the physical behaviors of the acoustic waves and the loss mechanisms. In addition, the temperature response of the devices was numerically calculated, showing relatively low temperature coefficients of frequency (TCF) of ~−38 ppm/K for the primary resonant mode. The LT-based XBARs were fabricated and characterized, which presents a multi-resonant mode over a wide frequency range (0.1~10 GHz). For the primary resonance around 4.1 GHz, the fabricated devices exhibited a high-quality factor (Bode-Q) ~ 600 and piezoelectric coupling (k_t²) ~ 2.84%, while the higher-harmonic showed a greater value of k_t² ~ 3.49%. To lower the resonant frequency of the resonator, the thin SiO₂ film (~20 nm) was sputtered on the suspended device, which created a frequency offset between the series and shunt resonators. Finally, a ladder-type narrow band filter employing five XBARs was developed and characterized. This work effectively demonstrates the performance and application potential of micro-acoustic resonators employing high-quality LT films. Full article

Objectives: This study aimed to evaluate the postoperative outcomes of the PreserFlo MicroShunt in Asian patients with exfoliation glaucoma. Methods: We used the Kaplan–Meier method to analyze 29 eyes of 29 patients with exfoliation glaucoma (mean age: 80.7 ± 8.3 years; 16 males; 24 eyes with intraocular lens implants; preoperative intraocular pressure [IOP]: 32.5 ± 9.3 mmHg; preoperative antiglaucoma medications: 3.4 ± 1.0; Asian ethnicity: 100%) who underwent PreserFlo MicroShunt surgery alone at Saneikai Tsukazaki Hospital from November 2022 to November 2023. The criteria for survival were a reduction in IOP of ≥20%, no additional glaucoma surgery, and IOP of 5–21 mmHg (condition 1), 5–18 mmHg (condition 2), and 5–15 mmHg (condition 3). Needling and glaucoma eye drops were considered qualified successes. Results: The mean follow-up period was 27.9 weeks, with a reoperation rate of 31% (9 cases). The complete and qualified success survival rates at 24 weeks were 56%, 52%, and 49%, and 67%, 59%, and 53% for conditions 1–3, respectively. The complete and qualified success survival rates at 48 weeks were 47%, 43%, and 45%, and 52%, 46%, and 48% for conditions 1–3, respectively. Conclusions: The postoperative outcomes of the PreserFlo MicroShunt in Asian patients with exfoliation glaucoma demonstrated an approximate 50% success rate at both 24 and 48 weeks, with a reoperation rate of approximately 30%. Caution is warranted when performing PreserFlo MicroShunt in patients with exfoliation glaucoma. Full article

To compare success rates of trabeculectomy (TE) and Preserflo MicroShunt (PMS) in heterogenous glaucoma cohorts with regards to different pre- and postoperative therapeutic regimens. Data of 187 glaucoma patients who either received TE (73 eyes) or PMS implantation (114 eyes) between January 2018 and December 2022 were retrospectively evaluated. Surgical success and failure rates were analyzed within six months of follow-up. Intraocular pressure (IOP) development over the course of follow-up was compared between both groups. Tertiary outcome measures were best-corrected visual acuity (BCVA), number and type of medications, frequency of postoperative complications and revision surgeries. Outcome measures underwent additional assessment based on subgroup categorizations, and failure time hazard ratios were computed. The success rates were comparable between both procedures (TE: 54.1%, PMS: 60.0%; p = 0.17). Both procedures showed significant IOP reduction (p < 0.01); however, overall IOP reduction was greater in the TE group than in the PMS group (TE: Reduction by 12 mmHg (188.9%), PMS: Reduction by 7 mmHg (51.3%); p = 0.01). The number of topical medications decreased significantly in both groups over the course of follow-up (TE: 4 to 0, PMS: 3 to 0; p < 0.01). While the number of complications and revision surgeries were similar in both groups, the time interval until the first revision surgery within the TE group was significantly shorter (TE: 13.5 d, PMS: 163 d; p = 0.01) than within the PMS group. No difference could be detected between TE and PMS with regard to the follow-up regimen. In particular, there was no significant difference in the need for 5-floururacil injections postoperatively (p = 0.29). Less invasive glaucoma surgery with the PMS appeared comparable to the TE within a heterogenous glaucoma cohort with regards to IOP development and freedom from medication. Full article

To evaluate the effectiveness of the PRESERFLO MicroShunt (PFM) in reducing intraocular pressure (IOP) ex vivo in porcine eyes using an infusion pump system and to simulate various IOP conditions, In this study, porcine eyes received increasing flows between 2 and 20 μL/min. IOP measurements were taken under conditions with and without the PFM [PFM (+) and PFM (−), respectively]. In the PFM (−) group, IOP increased from 7.4 mmHg to 46.3 mmHg as the flow rate increased from 2 μL/min to 20 μL/min. The rate of IOP reduction (%ΔIOP) rose with increasing flow rates, although the absolute IOP values achieved with the PFM insertion also increased. The correlation between IOPs in the PFM (−) conditions and the %ΔIOP was modeled as %ΔIOP = 22.4 Ln [PFM(−) IOP] − 41.7. According to this equation, IOP reduction by PFM insertion is 0% at IOPs of 6.4 mmHg or lower. IOP reductions of 10%, 20%, 30%, and 40% were observed when the pre-insertion IOPs were 10.1, 15.7, 24.6, and 38.4 mmHg, respectively. Achievable post-insertion IOP levels of ≤21 mmHg, ≤18 mmHg, ≤15 mmHg, and ≤12 mmHg corresponded to the initial IOPs of 33 mmHg, 26 mmHg, 20 mmHg, and 14.8 mmHg, respectively. In conclusion, the PFM effectively reduced IOP within a specific range of IOP values in an ex vivo experimental system. In clinical situations, the PFM is unlikely to be effective at low IOP levels. At higher levels, the PFM reduces IOP, but it may be insufficient to achieve the target IOP. Full article

Addressing challenges regarding Hybrid Optoelectronic Network-on-Chip systems, such as congestion control, their limited adaptability, and their inability to facilitate optoelectronic co-simulation, this study introduces an adaptive hybrid optoelectronic interconnection shunt structure tailored for reconfigurable array processors. Within this framework, an adaptive shunt routing algorithm and a low-loss non-blocking five-port optical router are developed. Furthermore, an adaptive hybrid optoelectronic interconnection simulation model and a performance statistical model, established using SystemVerilog and Verilog, complement these designs. The experimental results showcase promising enhancements: the designed routing algorithm demonstrates an average 17.5% improvement in mitigating congestion at network edge nodes; substantial reductions in the required number of cross waveguides and micro-ring resonators for optical routers lead to an average path insertion loss of only 0.522 dB. Moreover, the hybrid optoelectronic interconnection performance statistical model supports the design of routing strategies and topology structures, enabling resource usage, power consumption, insertion loss, and other performance metrics to be accurately assessed. Full article

This paper describes different variants of broadband and simple attenuator modules for beamforming applications, based on radio frequency micro electro-mechanical systems (RF-MEMS), framed within coplanar waveguide (CPW) structures. The modules proposed in the first part of this work differ in their actuation voltage, topology, and desired attenuation level. Fabricated samples of basic 1-bit attenuation modules, characterized by a moderate footprint of 690 × 1350 µm² and aiming at attenuation levels of −2, −3, and −5 dB in the 24.25–27.5 GHz range, are presented in their variants featuring both low actuation voltages (5–9 V) as well as higher values (~45 V), the latter ones ensuring larger mechanical restoring force (and robustness against stiction). Beyond the fabrication non-idealities that affected the described samples, the substantial agreement between simulations and measurement outcomes proved that the proposed designs could provide precise attenuation levels up to 40 GHz, ranging up to nearly −3 dB and −5 dB for the series and shunt variants, respectively. Moreover, they could be effective building blocks for future wideband and reconfigurable RF-MEMS attenuators. In fact, in the second part of this work, combinations of the discussed cells and other configurations meant for larger attenuation levels are investigated. Full article