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A triple-band bandpass filter (BPF) using stub loaded quarter-wavelength triple-mode resonators is presented in this letter. Based on the resonance characteristics analysis, it is found that the fundamental mode and the third harmonic in the quarter-wavelength resonator can be independently controlled by the length of quarter-wavelength resonator and the length of short-circuited stub. Furthermore, a new mode is achieved by a novel technique of loading an open-circuited stub on a short-circuited stub. Finally, triple-band BPF is designed, fabricated, and measured to verify the design principle. Good agreement is achieved between the theoretical, simulated and measured results.

A highly integrated three-state diplexer (TSD) on a single planar elliptical structure is for the first time presented in this paper. Three resonant modes are investigated in a planar elliptical resonator, e.g., two TM11 degenerate modes and one TM21 mode. These three resonant modes are designed to form three filtering channels, which are further combined to generate three states of a diplexer, namely, TSD. The planar elliptical triple-mode resonator is fed by three microstrip lines to form a triple-mode TSD. In order to validate the concept, the designed planar TSD is fabricated and measured. The measured results are in good agreement with the simulated ones.

A helical resonator with two-sectional different pitches is proposed in this paper. The frequency ratios of the first two resonant modes of the helical resonator can be tuned to desirable values in a certain range by adjusting the pitches. The proposed resonator is applied to design dual-band bandpass helical filters. To achieve control over dual-band filtering characteristics, a feeding structure with step-rectangular plate and a coupling window with three apertures are also proposed to realize the expected external quality factors and coupling coefficients in the two bands. To validate the design, a second order and a fourth order dual-band helical filters are fabricated and measured. The measured results show good agreement with simulation ones.

This paper presents a novel modified coaxial cavity resonator and its application to bandpass filters (BPF) with compact size. Unlike the conventional coaxial cavity resonator, the proposed resonator is made up of multi-metal-slices-loaded on the inner coaxial conductor within a single rectangle cavity. The technique with multi-metal-slices is applied to enhance the self-inductance and self-capacitance of the coaxial cavity resonator which leads to size reduction. Based on the research of position and size for the loading multi-metal-slices, an efficient way to load is proposed, Compared to the conventional coaxial cavity resonator, the central frequency can be reduced. Finally, a simulation example of BPF using this technique is presented to validate this attractive design concept.

This paper proposes a novel diplexer based on triple-mode dielectric-loaded cylindrical cavities. Such two metal cavities are designed to achieve two different frequency bands, while three resonant modes of a single cavity are classified as a TM mode and a pair of hybrid (HE) degeneration modes. An off-centered dielectric resonator instead of a traditional corner cuts perturbation or screws perturbation properly perturbs the two degenerate modes in the same cavity. Extensive study is then conducted to design this proposed diplexer. Finally, a diplexer prototype is fabricated using a brass cavity and it is tested for experimental verification of the predicted results. Good agreement between measurement and simulation is achieved.

Background Postoperative cholangitis is a common but severe complication after Kasai portoenterostomy for biliary atresia (BA). This study aimed to identify its prognostic factors. Methods Two sets of liver paraffin-embedded tissue samples were collected from BA patients who received Kasai portoenterostomy (n = 25 and n = 31, respectively). Patients were divided into non-cholangitis and cholangitis groups. The infiltration of CD4+, CD8+, CD45RO+, CD68+ cells and expression of Beclin1 were quantitatively evaluated in immunohistochemical analysis. Results Cholangitis group had a significantly lower CD8+ T cell infiltration but a higher CD45RO+ cell infiltration, and a lower Beclin1 level than non-cholangitis group (all P < 0.01). Multivariate logistic regression analysis indicated that infiltration of CD8+ cells (odds ratio [OR], 0.112; 95% confidence interval [CI], 0.022-0.577) and CD45RO+ cells (OR, 3.88; 95% CI, 1.37-11.03), and Beclin1 level (OR, 0.088; 95% CI, 0.018-0.452) were independent influence factors for early postoperative cholangitis. Receiver operating characteristic (ROC) analysis showed that area under ROC curve (AUROC) values for CD8+ cells, CD45RO+ cells and Beclin1 were 0.857, 0.738 and 0.900, respectively. Conclusion Our findings demonstrated the CD8+ cells, CD45RO+ cells and Beclin1 level possessed the prognostic value for early postoperative cholangitis following Kasai operation, which may be helpful to develop new prevention and treatment strategies for postoperative cholangitis.

A compact triple-mode dielectric resonator (DR) bandpass filter (BPF) based on a single waveguide cavity is proposed, while three resonant modes of a single cavity are classified as a TM mode and a pair of hybrid degenerate modes (HE modes). Two HE degeneration modes in a single metal cavity are excited by using an off-centered DR approach. They work together to constitute a three-pole passband with a fractional bandwidth of 2.7% at the central frequency of 2.53 GHz. To verify the proposed idea, the proposed triple-mode DR BPF is fabricated by using silver plated aluminum metal cavity, and the simulated and measured results are in good agreement. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1645–1647, 2016

This article presents a quad-band bandpass filter (QB-BPF) using a set of stub-loaded half-wavelength step impedance resonators operated at the second and third passbands (2.4/3.5 GHz) and a set of stub-loaded quarter-wavelength step impedance resonators operated at the first and fourth passbands (1.3/5.8 GHz), and the frequency ratio is 4.46 times. Furthermore, all the frequencies and bandwidths can be adjusted. Finally, the proposed filter is designed and fabricated. The measured results are in good agreement with the full-wave simulation results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2845–2848, 2014

Two types of modified open- or short-circuited stub-loaded $\lambda/4$ resonator and their applications to second- order dual-band bandpass filters are presented in this letter. Based on the resonance characteristics analysis, it is found that the first two resonant frequencies of the two resonators can be independently controlled. Furthermore, different frequency ratios can be achieved by loading different stubs. Finally, to illustrate the proposed idea, two second-order dual-band filters with controllable bandwidths are designed, fabricated and measured. The measured results are in good agreement with the full-wave simulation results.

A novel short-circuited stubs loaded λ/4 resonator and its application to third-order dual-band bandpass filter are presented in this paper. Based on the analysis of resonance characteristics, it is found that the characteristics of the first passband can be conveniently controlled by the two loading shunt stubs, whereas that of the second passband are fixed. A third-order dual-band bandpass filter is designed and fabricated. Simulated and measured results are agreed with each other.

In this letter, a quad-mode single band bandpass filter and a dual-mode dualband bandpass filter are designed and fabricated by the same structure (two coupled dual-mode loop resonators), which consist of an outer loop resonator with square-patch perturbation at the corner and a inner loop resonator with corner-cut perturbation at the corner. Four transmission zeros are realized in the stopbands to improve the selectivity of the two proposed bandpass filters. Good agreement is observed between simulated and measured performances.

This paper presents a quad-band filter using a set of stub-loaded quarter-wavelength resonators operated at the first and fourth passbands (1.8/5.8 GHz) and a set of stub-loaded half-wavelength SIRs operated at the second and third passbands (2.4/3.5 GHz). Furthermore, both of the loading stub are used to generate another passband. This study provides an effective method to design a quad-band filter with low insertion loss and compact size. Finally, the proposed filter is successfully fabricated and measured. It is shown that the measured and simulated performances are in good agreement.

Objective To report a new surgical technique for midshaft hypospadias repair without penile curvature. Methods From September 2007 to October 2010, 21 patients, aged 13 months to 8.9 years, underwent single-stage hypospadias repair by 1 surgeon. The skin incision was created around the meatus, and a long channel beneath the urethral plate was created through the incision to the apex of the glans. The inner preputial flaps were tubularized into a neourethra, which was then transposed to the ventral channel through a ventrolateral tunnel beneath Buck's fascia. Most of the neourethra was covered by the intact soft tissue of the distal ventral penis. The proximal portion of the neourethra was covered by Buck's and dartos fascia around the skin incision, and the skin incision was closed longitudinally. The length of the urethral defect and channel and the postoperative complications were collected and analyzed. Results A total of 21 patients underwent single-staged hypospadias repair. The average length of the channel was 30 mm (range 25-35). The average length of the neourethra was 35 mm (range 30 to 40). The mean operative time was 60 minutes (range 50-70). The mean hospital stay was 12 days (range 10-14). With an average follow-up of 20 months (range 6-37), no postoperative complication was detected. Conclusion This technique provides excellent short-term results for midshaft hypospadias without penile curvature and is a safe and simple solution.

Background Several types of congenital lesions can cause complete or incomplete obstruction of the intestine. Our purpose is to present 3 neonates with dual intestinal type I atresia, i.e., simultaneous obstructive lesions at 2 locations in which the atresia manifested as diaphragm-like tissue. Case presentation All 3 cases were female infants ranging in age from 2 to 14 months. The common symptom in all cases was intermittent persistent vomiting. In some cases the vomitus was bilious, and other symptoms included abdominal distention and delayed meconium passage. Prior surgeries at another hospital were unsuccessful at relieving the symptoms in one case. One case had dual lesions in the colon, one dual lesions in the duodenum, and one atresia at both the distal portion of the ileum and the descending colon. Surgical exploration and removal of the lesions at our hospital was successful in all cases, and the infants were discharged in good condition. Conclusions Type I atresia can manifest as a diaphragm-like tissue obstructing the continuity of gastrointestinal tract, and in rare cases multiple areas may be present. Base on the intermittent nature of the associated symptoms, diagnosis can be difficult and is often delayed. Physicians should be aware of this condition during the work-up of an infant with persistent intermittent vomiting.