Since Huygens structures with phase shift lead to beam rotation, this manuscript discusses a phase shifter structure for the Huygens surface based on Tapered Slot Transition in the frequency range of 9.95-10.2 GHz using Varactor diodes. By inducing an electric field along the tracks and placing diodes, the phase can be changed up to 200 degrees. With unit cells of 0.2  -that this size is the smallest possible size for beam rotation structures - and a mega cell of 4 unit cells, incident angles of 0-15 degrees can be converted to transmitted angles of 10-45 degrees. The unit cell has been fabricated and it is shown that the measurement results are in good agreement with the simulation one.

A reconfigurable compact small size multiband meander line power divider with low insertion loss using two Varactor diodes is presented in this paper. Design methods along with analysis equations are provided. The reconfigurable responses are realized by tuning the controlling voltages of the two Varactor diodes thereby resulting compact size and less loss. One diode is used to tune the return loss of the input port and the other diode is utilized to tune the return loss of the two output ports and the isolation between the two ports. The tuning frequency range is from 0.8 GHz to 1.2 GHz. By tuning the bias voltages of the diodes, power divider can operate in 0.8 GHz to 1.2 GHz frequency bands.  A reconfigurable power divider is designed, fabricated and measured to validate the proposed methods. The power divider has the merits of compactness, low insertion loss, good isolation between two output ports, good return loss, and only two Varactor diodes.

This paper proposes a new smart antenna beamforming scheme based on electronically steerable parasitic array radiator (ESPAR). The proposed method is capable of providing better capacity compared to the conventional ESPAR. The termination of each antenna element in this structure comprises a PIN diode in addition to a Varactor. Using PIN diode besides the Varactor provides more degrees of freedom which lead to better interference suppression. Moreover, in the proposed method the required tunable impedance range of the Varactors is dramatically reduced. The optimal values of the tunable loads in each simulation scenario repetition are attained iteratively using steepest descent method with a maximum cross correlation coefficient criterion. Simulation results show that the proposed scheme outperforms the conventional ESPAR technique with respect to interference suppression and capacity enhancement. To further validate the beamforming ability of the proposed method, a testbed was fabricated. Measurement results confirm that the proposed method can provide an acceptable beamforming capability close to the simulated beam.

Introduction: Various methods have been recommended to treat dentin sensitivity, including Laser therapy and CPP-ACP (Casein phosphopeptide-amorphous calcium phosphate). The aim of this study was to compare the effect of high-power diode laser 980 nm and CPP-ACP paste on the dentin hypersensitivity treatment (DH).Materials and Methods: In this single-blind clinical trial study, 96 dentin-sensitive teeth were randomly divided into three groups of 32, and the groups were treated with diode 980 nm laser, power 1 watt,30 seconds irridation, CPP-ACP paste and control group (guide radiation without laser irradiation). The level of sensitivity and pain were determined and compared before treatment, 15 minutes after the first and second sessions, one week, one month, and two months after the end of treatment. The data were evaluated with one-way variance statistical tests and Tukey's post hoc test (α = 0.05).Results: There was no significant difference between the groups in the average score of DH except for the eighth week. (p value > 0.05) In the eighth week, the average score of DH in the diode laser group (p value = 0.04) and paste containing CPP ACP (p value > 0.001) was significantly lower than the control group. However, there was no significant difference between these two test groups (p value = 0.18). Changes in the average of DH in the eighth week showed that in the pasted group containing CPP-ACP, reduced pain was more than the laser-treated group (p value = 0.046) and in the laser group it was more than the control group (p value = 0.01).Conclusion: Both treatments effectively reduced dentin sensitivity after two months, but there is no significant difference between high-power diode laser 980 and CPP-ACP paste in the treatment of dentinal hypersensitivity.

This paper presents a compact topology for implementing multiband bandpass filters. The design uses interconnected multimode resonators (MMRs) and multi-level impedance structures to achieve a specific frequency response. This approach simplifies the design of quadruple bandpass filters for 4G and 5G applications. Since line widths cannot be adjusted post-construction, resonance positions require tuning. To evaluate the filter design process, a prototype incorporating MMRs was designed, manufactured, and analyzed, demonstrating close alignment between analytical predictions and experimental measurements, despite no simulation or optimization being performed during the design phase, except for result verification.Additionally, a design criterion is established to facilitate the rapid and reliable synthesis of multiband responses by varying only a few geometrical parameters of the MMRs. A simulation of this structure was conducted using CST software to confirm the proposed theory's accuracy. A reverse-biased Varactor diode, which functions as a capacitor with specific admittance, is utilized to provide the necessary tuning capability. The paper also highlights the impact of the Varactor diode's admittance on resonance location adjustments. To validate the design, the authors present a fabricated prototype of the proposed filter, which features quarter bands at 1.8, 2.1, 2.7, and 3.4 GHz, achieving an attenuations greater than -15 dB. The quarter band filter is primarily used in wireless telecommunications networks. Due to their specialized design, these filters can process multiple frequency bands simultaneously, enhancing communication quality and increasing network capacity in crowded and interference-prone environments.

Aim: There are various approaches to accomplish dacryocystorhinostomy. Our aim has been to assess the results of transcanalicular laser assisted dacryocystorhinostomy. Patients and Methods: Seventeen patients underwent 19 transcanalicular laser assisted dacryocystorhinostomy from 2001 to 2002 in Khatam Hospital. Mean age of the patients was 36.4±8.47 years (range, 25 to 53), with female to male ratio of 13 (76%) to 4 (24%). Involvement of the right, left, and bilateral lacrimal system was seen in 8, 7, and 2 patients, respectively. Operations were performed under general anesthesia. After dilation of the inferior lacrimal punctum, a 600-micron laser probe was introduced through the inferior punctum and then to the lacrimal sac. A 4mm, 30-degree nasal endoscope was introduced into the ipsilateral nostril, enabling visualization of laser beam through the lateral nasal wall. The stoma was fashioned with the diode laser and enlarged under direct vision by low energy pulses. Next a bicanalicular silicone tube was routinely introduced and secured in place with knots. This was left in place for at least 12 weeks.Results: Two of the patients had bilateral involvement. Mean followup time was 8.97 months (range, 5-12). Four recurrences were observed in 19 procedures. Overall success rate of transcanalicular diode laser assisted dacryocystorhinostomy was 78.9%. Apart from recurrences, no complications were noted in intraoperative or postoperative period.Conclusion: Transcanalicular laser assisted dacryocystorhinostomy performed with a 600-micron contact fiber is a relatively simple, effective, and scarless procedure when used in conjunction with nasal endoscopy, in treatment of lacrimal pathways distal obstruction. The technique of opening the nasolacrimal sac from inside to outside reduces the risk of thermal damage to the orbital contents with the laser. In general, this technique is well comparable to external and endonasal techniques, although the success rate is lower. With more experiences and correcting the limitations, this technique would become more popular with higher success rates.

The paper reviews the past 11 years of literature on the application of diode lasers in atomic absorption spectrometry with graphite furnaces (GF), plasmas and flames as atomizers. Experimental arrangements and techniques for powerful absorption measurements as well as the theoretical background are covered. The analytical possibilities of high-resolution spectroscopy, including Dopplerfree techniques for isotope selective measurements and isotope dilution analysis are discussed and various applications of element-selective detection by diode laser atomic absorption in combination with separation techniques, such as liquid (LC) and gas chromatography (GC), and with laser ablation of solid samples, are presented.

Introduction: Laser-assisted vaporization of prostate tissue by means of the potassiumtitanyl-phosphate (KTP) laser is in clinical use. Alternative laser sources are available but are lacking clinical experience. The 980 nm wavelength diode laser provides good hemostasis, in addition to a more rapid ablation rate. The aim of this study is approving the capability, feasibility, and good post-operative outcome of vaporization of prostate by means of a diode laser in a long-term follow up.Methods: The light (980 nm, 100 W) of a diode laser was transmitted to prostate tissue. The study included 70 men suffering from bladder outlet obstruction due to benign prostatic hyperplasia (BPH). The prostatic lobes were vaporized within the prostatic capsule. Post-operative outcome and voiding were evaluated during a follow-up period of 24 months.Results: During surgery, no significant blood loss or any fluid absorption occurred. Catheters were removed in the 20.1±4.6 hours. All patients except two were satisfied with their voiding outcome. After removing the catheter, the mean peak urine flow rate significantly increased from 6.8±2.5 ml/s preoperatively to 15.6±3.1 ml/s postoperatively. No evidence of urgency, dysuria, hematuria, or incontinence was observed. Four patients required re-catheterization, and two of them needed consecutive TURP. After a 1-month, as well as after a 6-month, a 12-mouth, and a 1-year follow-up, all patients were still satisfied with the outcome.Conclusion: This long term experience showed that 100 W-980 nm-diode-laser vaporization prostatectomy was feasible and appeared to be safe and effective for quickly relieving bladder outlet obstruction due to BPH.