Non-cholera Vibrio spp. invasive infections in the summer following May 2023 flood disaster in Romagna, Italy: a case series

Non-cholera Vibrio spp. includes ubiquitous organisms living in aquatic environments. Their occurrence is associated with global warming and meteorological disasters. In May 2023 the Romagna region, Italy, was affected by severe floods. In the following 15 weeks we observed 5 patients with invasive infections caused by V. vulnificus (3/5) and V. harveyi (2/5). All patients (median age 77 years) had medical comorbidities and shared exposure to seawater. Two patients needed surgery; 2 died. In conclusion, we observed an increased burden of Vibrio spp. invasive infections after May 2023 floods, affecting old patients with predisposing medical conditions.

Model of Care for Microelimination of Hepatitis C Virus Infection among People Who Inject Drugs

Background: People who inject drugs (PWID) are the largest group at risk for HCV infection. Despite the direct acting antivirals (DAA) advancements, HCV elimination has been hindered by real-life difficulties in PWID. Aims: This study aimed to assess the impact of a multidisciplinary intervention strategy where HCV screening, treatment and follow-up were performed at the same location on efficacy and safety of DAA-therapy in real-life PWID population. Methods: All HCV-infected PWID referred to five specialized outpatient centers for drug addicts (SerDs) in Northern Italy were prospectively enrolled from May 2015 to December 2019. Hepatologists and SerDs healthcare workers collaborated together in the management of PWID inside the SerDs. Sustained virologic response (SVR), safety of treatment, proportion of patients lost to follow-up and reinfection rate were evaluated. Results: A total of 358 PWID started antiviral treatment. About 50% of patients had advanced fibrosis/cirrhosis, 69% received opioid substitution treatment, and 20.7% self-reported recent injecting use. SVR was achieved in 338 (94.4%) patients. Two patients died during treatment; one prematurely discontinued, resulting in a non-responder; twelve were lost during treatment/follow-up; and five relapsed. No serious adverse events were reported. SVR was lower in recent PWID than in former ones (89.2% vs. 95.8%; p = 0.028). Seven reinfections were detected, equating to an incidence of 1.25/100 person-years. Reinfection was associated with recent drug use (OR 11.07, 95%CI 2.10–58.38; p = 0.005). Conclusion: Our embedded treatment model could be appropriate to increase the linkage to care of HCV-infected PWID. In this setting, DAA regimens are well tolerated and highly effective, achieving a lower rate of reinfection.

The impact of COVID-19 outbreak on urolithiasis emergency department admissions, hospitalizations and clinical management in central Italy: a multicentric analysis

Introducción y objetivos

Nuestro objetivo fue evaluar el impacto de la enfermedad del coronavirus de 2019 (COVID-19) en los ingresos en los servicios de urgencias (SU), las hospitalizaciones y el manejo clínico de los pacientes con urolitiasis.

Pacientes y métodos

Realizamos un análisis retrospectivo multicéntrico de las admisiones en los servicios de urgencias de tres departamentos de urología de gran volumen (uno directamente implicado en el tratamiento de los pacientes de COVID-19 y dos no implicados) en Roma (Italia) entre marzo y abril de 2020 y en el mismo período de 2019. Se realizó un análisis estadístico del número de admisiones por urolitiasis, la tasa de complicaciones, hospitalización y el tipo de tratamiento recibido.

Resultados

Fueron incluidos 304 pacientes en el análisis. Se observó una reducción significativa en el número global de pacientes ingresados en urgencias por urolitiasis entre 2019 y 2020 (48,8%). Además, con respecto a la elección del tratamiento de los pacientes hospitalizados, se informó un aumento estadísticamente significativo de los procedimientos de extracción de cálculos en comparación con el drenaje urinario en 2020 (p = 0,015).

Conclusiones

Durante la pandemia de la COVID-19 en Roma ha habido una reducción significativa de los ingresos en urgencias por urolitiasis. Los pacientes ingresados en el SU tuvieron más complicaciones, necesitaron hospitalización con más frecuencia y en cuanto al manejo clínico, se prefirió la extracción temprana de los cálculos, en vez del drenaje urinario. Todos los urólogos deben ser conscientes de que en los próximos meses podrían enfrentar un mayor número de admisiones por urolitiasis y un manejo de casos más complicados.

Tunable narrow band optical reflector based on indirectly coupled micro ring resonators

This paper presents a novel narrow band wavelength selective optical reflector implemented by indirectly coupling two micro ring resonators in silicon-on-insulator technology. The device is studied using an analytical model based on the transfer matrix method. With the proposed configuration, by electrically driving the integrated micro heaters, a single reflection wavelength with narrow bandwidth can be tuned. The experimental results show a good agreement with the model outcomes. The average measured reflectivity over a wavelength span of 37 nm is 0.55, with a peak of about 50 pm full-width-half-maximum, which corresponds to a quality factor of ∼30, 000. The proposed device can offer an alternative approach to realize compact reflective structures for single wavelength reflection operations in photonic integrated circuits.

Array of plasmonic Vivaldi antennas coupled to silicon waveguides for wireless networks through on-chip optical technology - WiNOT

Optical technology applied to on-chip wireless communication is particularly promising to overcome the performance limitations of the state-of-the-art networks on-chip. A key enabling component for such applications is the plasmonic antenna coupled to conventional silicon waveguides, which can guarantee full compatibility with standard optical circuitry. In this paper, we propose an antenna array configuration based on tilted plasmonic Vivaldi antennas coupled to a silicon waveguide. The details of the single antenna and of the array design are reported. The radiation characteristics of the array are suitable for on-chip point-to-point communication, i.e. in-plane maximum gain of 14.70 dB for an array with five antennas. The array exploits a travelling wave feeding scheme and, therefore, is compact in size (about 3.5 µm × 8.7 µm ).

Assessment of the orthogonal and non-orthogonal coupled-mode theory for parallel optical waveguide couplers

The coupled-mode theory (CMT) is a powerful approach routinely used to calculate the effects of spatial mode interactions in perturbed structures, such as optical waveguides. One of its basic hypotheses requires that perturbations are weak. This is usually not the case for devices fabricated with modern semiconductor-based technologies. In this paper, the CMT is studied in these critical cases to assess its validity. Attention will be focused on the quite common case of parallel coupled waveguides. For these structures, results can in fact be compared to the exact ones, obtained using super-modes. The study will show that not all the possible expressions of the coupling coefficients are equivalent, and which one can be pragmatically used to obtain results with minimum errors with respect to exact solutions.

Integrated Vivaldi plasmonic antenna for wireless on-chip optical communications

In this paper we propose a novel hybrid optical plasmonic Vivaldi antenna for operation in the standard C telecommunication band for wavelengths in the 1550 nm range. The antenna is fed by a silicon waveguide and is designed to have high gain and large bandwidth. The shape of the radiation pattern, with a main lobe along the antenna axis, makes this antenna suitable for point-to-point connections for inter- or intra-chip optical communications. Direct port-to-port short links for different connection distances and in a homogeneous environment have also been simulated to verify, by comparing the results of a full-wave simulation with the Friis transmission equation, the correctness of the antenna parameters obtained via near-to-far field transformation.

Fournier's gangrene: Clinical case and review of the literature

Fournier's gangrene is a life-threatening acute necrotizing fasciitis of perianal,genitourinary and perineal areas. Nowadays, is well known that Fournier gangrene is almost never an idiopathic disease. In this article we report a case of a 70-year-old patient that initially was not treated properly. The gold standard therapy of the Fournier's gangrene remains today a complete, early and extended surgical debridement.

Holey fiber mode-selective couplers

Directional mode coupling in an asymmetric holey fiber coupler is demonstrated both numerically and experimentally for the first time. The holey fiber mode couplers have interesting spectral characteristics and are also found to exhibit increased dimensional tolerances. Following a design based on numerical investigations, a dual-core polymer holey fiber coupler for LP(01) and LP(11) mode multiplexing was fabricated via a drilling and drawing technique. The measurements are compared with the simulation results.

Histopathological findings and proliferative activity of canine sebaceous gland tumours with a predominant reserve cell population

Sebaceous gland tumours represent the third most common skin tumours in dogs, but diagnostic criteria for tumours with basal differentiation (i.e. sebaceous epithelioma) are poorly defined and there is lack of correlation with biological behaviour. The aim of this study was to identify the main histological criteria associated with malignancy in 30 canine sebaceous gland tumours with a predominant reserve cell population. For each case, tumour proliferative activity was assessed by determining mitotic index and the Ki67/MIB-1 index. Additional histological features included endophytic or exophytic growth, proportion of reserve/intermediate/mature cells, connection to the epidermis, nuclear characteristics, peripheral invasion, neoplastic emboli and necrosis. Mitotic and Ki67 indexes were variable, but correlated (R = 0.66; P < 0.001), and both were significantly higher in infiltrative tumours (P = 0.018 and P < 0.001, respectively). No significant difference in histological features was observed between tumours comprised of more or less than 90% reserve cells, nor among tumours showing proliferative activity in sebocytes. This study suggests that high proliferative activity and peripheral invasion should be considered the most significant parameters for the differentiation between benign and malignant sebaceous gland tumours. Furthermore, the incidence of circumanal gland and testicular tumours in these dogs was significantly higher compared with an age-matched control population, suggesting a potential androgen-related pathway for the tumourigenesis of canine sebaceous gland neoplasms.

Previous infection and the risk of ischaemic stroke in Italy: the IN2 study

BACKGROUND AND PURPOSE

There is an increasing interest in new risk factors for ischaemic stroke. Acute and chronic infections could contribute to different aetiological mechanisms of atherosclerosis that lead to cerebrovascular disease. The aim of this study was to investigate the hypothesis that previous infections and Chlamydia pneumoniae in particular increase the risk of ischaemic stroke in the population.

METHODS

This was a prospective case-control study involving 11 Italian stroke units. Controls were age- and sex-matched with cases, represented by patients admitted to hospital for acute ischaemic stroke. For each participant classical vascular risk factors and previous inflammatory and infectious events up to 1 month before were registered. Blood samples were collected to analyse inflammatory markers and titres of antibodies against C. pneumoniae.

RESULTS

A total of 1002 participants were included (mean age 69 years) with 749 ischaemic stroke patients. Infections occurred within 1 month previously in 12% of the entire sample with a higher prevalence in the case group (14.4% vs. 3.9%). At multivariate analysis of the seropositivity of IgA antibodies against C. pneumoniae increased the risk of stroke significantly (relative risk 2.121; 95% confidence interval 1.255-3.584) and an early previous infection (up to 7 days before the event) contributed to a rise in probability of acute cerebral ischaemia (relative risk 3.692; 95% confidence interval 1.134-6.875).

CONCLUSIONS

Early previous infections and persistent chronic infection of C. pneumoniae could contribute to increase the risk of ischaemic stroke significantly, in the elderly especially.

Tunable silicon photonics directional coupler driven by a transverse temperature gradient

A compact directional coupler fabricated on a silicon photonic platform is presented, with a power-splitting ratio that can be tuned through a transverse temperature gradient induced by a laterally shifted integrated heater. The tuning mechanism exploits the thermally induced phase velocity mismatch between the coupled modes of the silicon waveguides. The positions of the integrated heater and the waveguide design are optimized to maximize the tuning range and to reduce electric power consumption. Asynchronous devices with an intrinsic phase mismatch are demonstrated to be more efficient, providing a tunable coupled power from 0.7 to 0.01 with 36 mW maximum power dissipation.

Reconfigurable silicon filter with continuous bandwidth tunability

We present the design and the fabrication of compact tunable silicon-on-insulator bandpass filters based on the integration of a Mach-Zehnder interferometer with ring resonators and activated via thermo-optic phase shifters. The proposed architecture provides wide filter bandwidth tunability from 10% to 90% of the free spectral range preserving the filter off-band rejection. Possible applications are channel subset selection in wavelength division multiplexing optical systems, adaptive filtering to signal bandwidth, and reconfigurable filters for gridless networking.

Silencing of GSTP1, a prostate cancer prognostic gene, by the estrogen receptor-β and endothelial nitric oxide synthase complex

We recently identified in prostate tumors (PCa) a transcriptional prognostic signature comprising a significant number of genes differentially regulated in patients with worse clinical outcome. Induction of up-regulated genes was due to chromatin remodeling by a combinatorial complex between estrogen receptor (ER)-β and endothelial nitric oxide synthase (eNOS). Here we show that this complex can also repress transcription of prognostic genes that are down-regulated in PCa, such as the glutathione transferase gene GSTP1. Silencing of GSTP1 is a common early event in prostate carcinogenesis, frequently caused by promoter hypermethylation. We validated loss of glutathione transferase (GST) P1-1 expression in vivo, in tissue microarrays from a retrospective cohort of patients, and correlated it with decreased disease-specific survival. Furthermore, we show that in PCa cultured cells ERβ/eNOS causes GSTP1 repression by being recruited at estrogen responsive elements in the gene promoter with consequential remodeling of local chromatin. Treatment with ERβ antagonist or its natural ligand 5α-androstane-3β,17β-diol, eNOS inhibitors or ERβ small interference RNA abrogated the binding and reversed GSTP1 silencing, demonstrating the direct involvement of the complex. In vitro, GSTP1 silencing by ERβ/eNOS was specific for cells from patients with worse clinical outcome where it appeared the sole mechanism regulating GSTP1 expression because no promoter hypermethylation was present. However, in vivo chromatin immunoprecipitation assays on fresh PCa tissues demonstrated that silencing by ERβ/eNOS can coexist with promoter hypermethylation. Our findings reveal that the ERβ/eNOS complex can exert transcriptional repression and suggest that this may represent an epigenetic event favoring inactivation of the GSTP1 locus by methylation. Moreover, abrogation of ERβ/eNOS function by 3β-adiol emphasizes the significance of circulating or locally produced sex steroid hormones or their metabolites in PCa biology with relevant clinical/therapeutic implications.

Evidence for bovine besnoitiosis being endemic in Italy--first in vitro isolation of Besnoitia besnoiti from cattle born in Italy

Until 2009, bovine besnoitiosis had never been considered endemic in Italy and the only report on the disease in this country referred to animals imported from France shortly before. However, recently, an autochthonous outbreak of bovine besnoitiosis was reported in four herds located at the intersection of the borders between Emilia-Romagna, Toscana and Marche (Northern Apennine Mountains), which has led to an increased awareness concerning this disease. The present study describes a further outbreak of bovine besnoitiosis in Italy. The afflicted herd was a dairy herd with no evidence for contact with cattle from regions known to be endemic for bovine besnoitiosis. The farm investigation was initiated after a three-year old Holstein Friesian dairy cow with generalized thickening and lichenification of the skin was diagnosed with bovine besnoitiosis. The clinical diagnosis was confirmed by gross pathology, histopathology, serology and PCR. Bradyzoites released from tissue cysts obtained from the skin of this animal enabled the first in vitro isolation of Besnoitia besnoiti in Italy. This isolate was named Bb-Italy1. Sequencing of a 2118 bp spanning region including the complete internal transcribed spacer 1 and parts of the 18S and the 5.8S rRNA gene from DNA extracted from skin-derived zoites revealed a 99.9% identity to sequences known for other B. besnoiti isolated from cattle in Europe. Two GKO mice which had been inoculated intraperitoneally with bovine skin-derived bradyzoites became ill 7 days post inoculation. Parasitophorous vacuoles with multiplying zoites were observed in the cell culture inoculated with peritoneal fluids of these mice and a B. besnoiti infection in the mice and in the cell culture could be confirmed by real-time PCR. A serological investigation in the afflicted herd using immunoblots and an immunofluorescent antibody test (IFAT) revealed an overall herd seroprevalence of 9.7% (31/321), whereas within the female animals older than 2 years 17.0% (29/171) of the dams were tested positive. With one exception, an imported cow from Germany, all the seropositive animals were born in Italy. In connection with previously described autochthonous cases of bovine besnoitiosis the case described herein suggests that bovine besnoitiosis should be considered endemic in Italy.

Evidence for bovine parafilariosis in Italy: first isolation of Parafilaria bovicola (Tubangui, 1934) from autochthonous cattle

In May and July 2010 and in March 2011, the presence of multiple bleeding nodules at the level of the neck, shoulders, withers, back and rump in five cattle from three herds in north-central Italy were observed. A diagnosis of parafilariosis was made. Fragments of adult females of Parafilaria bovicola could be identified from the derma of three to five bioptic extirpates. Larvated eggs and free larvae were observed in serohemorrhagic exudates. This paper is the first report of the occurrence of parafilariosis in Italy and subsequent to the various outbreaks reported, it can now be said that bovine parafilariosis is also currently present in Italy.

A case of aseptic pleuropericarditis in a patient with chronic plaque psoriasis under methotrexate therapy

Methotrexate may rarely provoke serositis, even with low doses and after just a few weeks of therapy. We report here a rare case of pleuropericarditis due to methotrexate. The effusion resolved after the withdrawal of the drug and the beginning of anti-inflammatory therapy; there was no relapse during a 10-month follow-up.

High performance mode adapters based on segmented SPE:LiNbO3 waveguides

We propose a new mode adapter which allows more efficient launching of the optical power selectively in the fundamental mode of a multimode waveguide. Theoretical and experimental results confirm that such a mode adapter increases the performances in terms of coupling efficiency, coupling tolerances and transmitted power with respect to previously proposed solutions. Proof of principle of device operation is obtained with a simple Coupled Mode Theory model. Experimental results are obtained at a wavelength of 840 nm in Lithium Niobate Soft Proton Exchanged waveguides and agree very well with theoretical predictions.

Closure of the stop-band in photonic wire Bragg gratings

Photonic Wire Bragg Gratings, made by periodic insertion of lateral rectangular recesses into photonic wires in silicon-on-insulator, can provide large reflectivity with short device lengths because of their large index contrast. This type of design shows a counter-intuitive behaviour, as we demonstrate - using experimental and numerical data - that it can have low or null reflectance, even for large indentation values. We provide physical insight into this phenomenon by developing a model based on Bloch mode theory, and are able to find an analytical expression for the frequency at which the grating does not sustain the stop-band. Finally we demonstrate that the stop-band closing effect is a general phenomenon that may occur in various types of periodic device that can be modeled as transmission line structures.

In vitro effect of amikacin on rat and human detrusor muscle contraction

INTRODUCTION

Normal and abnormal bladder contractions are principally mediated by acetylcholine released from postganglionic parasympathetic nerves. Since amikacin was reported to affect neurotransmission by a prejunctional mechanism, we investigated the effect of amikacin on isolated detrusor smooth muscle contraction to further evaluate its potential relaxant properties.

MATERIALS AND METHODS

Detrusor smooth muscle obtained from 15 rats and 8 patients undergoing surgery were studied through measurement of isometric muscular contraction induced with electrical field stimulation (EFS) (10-60 Hz), carbachol (10(-7) to 10(-3)M) and nicotine (10(-7) to 10(-3)M) in the presence or absence of 1 mM amikacin in a low-Ca medium.

RESULTS

Amikacin (1 mM) significantly reduced EFS-induced contraction of isolated rat and human detrusor muscle by 33 +/- 6.57% (p < 0.005) and 40 +/- 1.14% (p < 0.001), respectively. Contraction was restored after addition of calcium chloride (1 mM). The effect of amikacin was comparable to that of magnesium ions. Rat and human detrusor contractile response to nicotine was inhibited by 70 +/- 8.27% (p < 0.001) and 64 +/- 14.09% (p < 0.01) after the addition of amikacin (1 mM), while no significant effect was observed on carbachol-induced stimulation.

CONCLUSION

Amikacin significantly inhibited detrusor contraction evoked by prejunctional stimulation in vitro, suggesting a depressant effect on autonomic neurotransmission in urinary bladder.

Avoided-crossing-based liquid-crystal photonic-bandgap notch filter

We demonstrate a highly tunable deep notch filter realized in a liquid-crystal photonic-bandgap (LCPBG) fiber. The filter is realized without inducing a long-period grating in the fiber but simply by filling a solid-core photonic-crystal fiber with a liquid crystal and exploiting avoided crossings within the bandgap of the LCPBG fiber. The filter is demonstrated experimentally and investigated using numerical simulations. A high degree of tuning of the spectral position of the deep notch is also demonstrated.

The stroke in an emergency: the grey areas

In spite of the development of advanced technologies, diagnosis and therapy for an ictus in emergency still pose difficulties in a significant percentage of cases. Diagnostic problems are encountered both when faced with focal symptoms and in the presence of disturbances to consciousness, confusional states, vertigo or cephalea. The most significant therapeutic problems, on the other hand, are encountered in the case of extended cardioembolic ischaemias, haemorrhages from venous thrombosis and intradural arterial dissections (eventual antithrombotic treatment), when faced with a large cerebral oedema (eventual medical and/or surgical treatment), or in indicating surgery for intraparenchymal haemorrhages or symptomatic stenotic carotids.

A novel approach for accurate prediction of spontaneous passage of ureteral stones: Support vector machines

The objective of this study was to optimally predict the spontaneous passage of ureteral stones in patients with renal colic by applying for the first time support vector machines (SVM), an instance of kernel methods, for classification. After reviewing the results found in the literature, we compared the performances obtained with logistic regression (LR) and accurately trained artificial neural networks (ANN) to those obtained with SVM, that is, the standard SVM, and the linear programming SVM (LP-SVM); the latter techniques show an improved performance. Moreover, we rank the prediction factors according to their importance using Fisher scores and the LP-SVM feature weights. A data set of 1163 patients affected by renal colic has been analyzed and restricted to single out a statistically coherent subset of 402 patients. Nine clinical factors are used as inputs for the classification algorithms, to predict one binary output. The algorithms are cross-validated by training and testing on randomly selected train- and test-set partitions of the data and reporting the average performance on the test sets. The SVM-based approaches obtained a sensitivity of 84.5% and a specificity of 86.9%. The feature ranking based on LP-SVM gives the highest importance to stone size, stone position and symptom duration before check-up. We propose a statistically correct way of employing LR, ANN and SVM for the prediction of spontaneous passage of ureteral stones in patients with renal colic. SVM outperformed ANN, as well as LR. This study will soon be translated into a practical software toolbox for actual clinical usage.

Pharmacokinetic Study of Intravesical Gemcitabine in Carcinoma in situ of the Bladder Refractory to Bacillus Calmette-Guérin Therapy

INTRODUCTION

Gemcitabine, a chemotherapeutic agent, has been shown to be active against transitional cell cancer of the bladder. The aim of the study was to determine the pharmacokinetic profile of gemcitabine, administered intravesically in patients with carcinoma in situ(CIS).

MATERIAL AND METHODS

Nine patients with CIS refractory to intravesical bacillus Calmette-Guérin (BCG) therapy were enrolled. Gemcitabine was given in 50 ml 0.9% NaCl by catheterization and held in the bladder for 1 h, once weekly for 6 consecutive weeks. The pharmacokinetics for gemcitabine metabolites were performed in plasma and serum. Dose levels were: 1,000, 1,250, and 1,500 mg. Clinical evaluation was repeated 4 weeks after therapy and thereafter every 6 months.

RESULTS

Grade-1 neutropenia was observed only in 1 patient. Grade-1 urinary frequency and hematuria were observed in 1 and 3 patients, respectively. No grade 2-4 toxicity or clinically relevant myelosuppression were observed. Gemcitabine was detectable in serum, but with an irrelevant pharmacological effect, in only 1 patient treated with 1,500 mg of gemcitabine. With regard to activity, after 6 instillations of this drug, 4 complete responses were observed.

CONCLUSION

Intravesical gemcitabine is well tolerated and safe. No systemic absorption with a clinical or pharmacological effect was detected and only slightly irritative bladder symptoms were observed. These results warrant further investigation in phase-II trials.

[Transitional cell carcinoma involvement of the prostate]

Transitional cell carcinoma of the prostate (PTCC) has become a well recognized entity and is increasing in incidence due to the growing awareness of and search for. PTCC is part of the well known pan-urothelial disease: particularly the urologist must always consider the prostate in the management of superficial and invasive bladder cancer. Most cases are diagnosed in association with bladder cancer (secondary PTCC): primary prostatic transitional cell carcinoma arises "de novo" as the first tumor of the prostate urothelium and is rare. Prognosis depends on the prostate invasion degree. No reliable staging system is presently available. Non-invasive PTCC can be successfully treated with conservative means (TUR +/- BCG) whereas stromal invasive PTCC must be aggressively treated with radical cystectomy. PTCC can interphere with surgeon's decisions about urinary diversion in patients undergoing radical cystectomy for urothelial cancer.

Continuously tunable devices based on electrical control of dual-frequency liquid crystal filled photonic bandgap fibers

We present an electrically controlled photonic bandgap fiber device obtained by infiltrating the air holes of a photonic crystal fiber (PCF) with a dual-frequency liquid crystal (LC) with pre-tilted molecules. Compared to previously demonstrated devices of this kind, the main new feature of this one is its continuous tunability due to the fact that the used LC does not exhibit reverse tilt domain defects and threshold effects. Furthermore, the dual-frequency features of the LC enables electrical control of the spectral position of the bandgaps towards both shorter and longer wavelengths in the same device. We investigate the dynamics of this device and demonstrate a birefringence controller based on this principle.