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1.
Sensors (Basel) ; 24(5)2024 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-38474998

RESUMEN

A fully integrated 24-GHz radar transceiver with one transmitter (TX) and two receivers (RXs) for compact frequency modulated continuous wave (FMCW) radar applications is here presented. The FMCW synthesizer was realized using a fractional-N phase-locked loop (PLL) and programmable chirp generator, which are completely integrated in the proposed transceiver. The measured output phase noise of the synthesizer is -80 dBc/Hz at 100 kHz offset. The TX consists of a three-bit bridged t-type attenuator for gain control, a two-stage drive amplifier (DA) and a one-stage power amplifier (PA). The TX chain provides an output power of 13 dBm while achieving <0.5 dB output power variation within the range of 24 to 24.25 GHz. The RX with a direct conversion I-Q structure is composed of a two-stage low noise amplifier (LNA), I-Q generator, mixer, transimpedance amplifier (TIA), a two-stage biquad band pass filter (BPF), and a differential-to-single (DTS) amplifier. The TIA and the BPF employ a DC offset cancellation (DCOC) circuit to suppress the strong reflection signal and TX-RX leakage. The RX chain exhibits an overall gain of 100 dB. The proposed radar transceiver is fabricated using a 65 nm CMOS technology. The transceiver consumes 220 mW from a 1 V supply voltage and has 4.84 mm2 die size including all pads. The prototype FMCW radar is realized with the proposed transceiver and Yagi antenna to verify the radar functionality, such as the distance and angle of targets.

2.
Arch Plast Surg ; 48(6): 583-589, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34818703

RESUMEN

BACKGROUND: In prosthesis-based breast reconstruction patients, the drain tends to be kept in place longer than in patients who undergo only mastectomy. Postoperative arm exercise also increases the drainage volume. However, to preserve shoulder function, early exercise is recommended. In this study, we investigated the effect of early exercise on the total drainage volume and drain duration in these patients. METHODS: We designed a prospective randomized trial involving 56 patients who underwent immediate breast reconstruction following mastectomy using tissue expanders. In each group, the patients were randomized either to perform early arm exercises using specific shoulder movement guidelines 2 days after surgery or to restrict arm movement above the shoulder height until drain removal. The drain duration and the total amount of drainage were the primary endpoints. RESULTS: There were no significant differences in age, height, weight, body mass index, or mastectomy specimen weight between the two groups. The total amount of drainage was 1,497 mL in the early exercise group and 1,336 mL in the exercise restriction group. The duration until complete removal of the drains was 19.71 days in the early exercise group and 17.11 days in the exercise restriction group. CONCLUSIONS: Exercise restriction after breast reconstruction did not lead to a significant difference in the drainage volume or the average time until drain removal. Thus, early exercise is recommended for improved shoulder mobility postoperatively. More long-term studies are needed to determine the effect of early exercise on shoulder mobility in prosthesis-based breast reconstruction patients.

3.
J Plast Reconstr Aesthet Surg ; 74(8): 1801-1806, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33358674

RESUMEN

INTRODUCTION: The effect of radiation on uncomplicated postoperative scars is unclear. This study aimed to analyze irradiated and non-irradiated scars in patients with unilateral breast cancer, who underwent oncoplastic breast reduction surgery and radiation therapy (RT), to identify how postoperative scar changes with radiation. METHODS: Twenty breast scars in 10 patients were analyzed after unilateral breast-conserving surgery, oncoplastic breast reduction, and RT. Scars were assessed using the Vancouver scar scale (VSS) by two independent blinded observers and three-dimensional scar analysis camera. Paired t-test between irradiated and non-irradiated scars in each patient and correlation of scar score differences with potential contributing factors were analyzed. RESULTS: The VSS was significantly lower for the irradiated scar than that for the non-irradiated contralateral scar (1.40 vs. 4.05, p = 0.001), although time interval from the last radiation to scar assessment had a negative correlation with paired differences of VSS (Spearman's correlation coefficient: -0.637, p = 0.048). Compared with the non-irradiated scar, the irradiated scar showed a significantly high level of hemoglobin (1.04 vs. 1.26, p = 0.017) and melanin (0.55 vs. 0.63, p = 0.03). CONCLUSIONS: Postoperative scars with radiation showed better results in objective and subjective assessments than scars without radiation. These findings suggest that radiation has a positive effect on general scar maturation.


Asunto(s)
Neoplasias de la Mama/cirugía , Cicatriz/radioterapia , Complicaciones Posoperatorias/radioterapia , Adulto , Femenino , Humanos , Mamoplastia , Mastectomía , Persona de Mediana Edad , Estudios Prospectivos
4.
Arch Craniofac Surg ; 21(5): 309-314, 2020 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-33143400

RESUMEN

Reconstructions of extensive composite scalp and cranial defects are challenging due to high incidence of postoperative infection and reconstruction failure. In such cases, cranial reconstruction and vascularized soft tissue coverage are required. However, optimal reconstruction timing and material for cranioplasty are not yet determined. Herein, we present a large skull defect with a chronically infected wound that was not improved by repeated debridement and antibiotic treatment for 3 months. It was successfully treated with anterolateral thigh (ALT) free flap transfer for wound salvage and delayed cranioplasty with a patient-specific polyetheretherketone implant. To reduce infection risk, we performed the cranioplasty 1 year after the infection had resolved. In the meantime, depression of ALT flap at the skull defect site was observed, and the midline shift to the contralateral side was reported in a brain computed tomography (CT) scan, but no evidence of neurologic deterioration was found. After the surgery, sufficient cerebral expansion without noticeable dead-space was confirmed in a follow-up CT scan, and there was no complication over the 1-year follow-up period.

5.
Arch Craniofac Surg ; 21(4): 219-224, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32867410

RESUMEN

BACKGROUND: Repair of the orbital floor following trauma or tumor removal remains a challenge because of its complex three-dimensional shape. The purpose of the present study is to understand normal orbital floor anatomy by investigating its differences across four groups (Caucasian American and East Asian, males and females) via facial bone computed tomography (CT). METHODS: A total of 48 orbits in 24 patients between 20 and 60 years of age were evaluated. Although most patients underwent CT scanning following trauma, the orbital walls were intact in all patients. Linear and angular measurements of the orbital floor were obtained from CT images. RESULTS: Orbital floor width, length, angle between the orbital floor and medial wall, and distance from the inferior orbital rim to the lowest point of the orbital floor did not show a statistically significant difference between groups. Angles made by the infraorbital rim, the lowest point of the floor, and the anterior border of the infraorbital fissure were statistically significantly wider in East Asian females than in male groups. The floor depth in East Asian females was significantly smaller compared to all the other groups. CONCLUSION: East Asian female population had smaller curvature and depth of an orbital floor than the other groups, which means racial and sex-related differences should be considered in the orbital floor reconstruction.

7.
Chem Commun (Camb) ; 49(99): 11698-700, 2013 Dec 25.
Artículo en Inglés | MEDLINE | ID: mdl-24195108

RESUMEN

A unique system has been developed for quantifying G-quadruplex forming DNA down to picomolar levels for future applications in telomeric assessment. Pyrene-imidazolium captured in high amounts on the surface of reduced graphene oxide shells allows specific DNA sequence detection by complex formation resulting in release and fluorescence enhancement of pyrene-imidazolium.


Asunto(s)
ADN/análisis , Colorantes Fluorescentes/química , G-Cuádruplex , Grafito/química , Imidazoles/química , Pirenos/química , Secuencia de Bases , Espectrometría de Fluorescencia
8.
ACS Nano ; 7(3): 2595-601, 2013 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-23451724

RESUMEN

Chiral templating and enantioselective separations are demonstrated on graphene surfaces as directed by encapsulated silica nanotubes. Electrostatic assembly of helical silica nanotubes within graphene sheets results in a hybrid material with the electrochemical properties of graphene and the capability for chiral recognition. Control of the silica nanotube helicity within the graphene hybrid provides a means for directed chiral templating of guest molecules on the outer graphene surface as revealed in the chiral transcription of N(1),N(3),N(5)-tri(4-pyridinyl)cyclohexane-1,3,5-tricarboxamide as well as polyallylamine into supramolecular templated assemblies. Changing the helicity of the internal nanotube also provides control over enantiomer selectivity as demonstrated by the chiral separation of racemic mixtures of phenylalanine, tryptophan, and alanine derivatives.

9.
Chem Commun (Camb) ; 49(21): 2109-11, 2013 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-23323267

RESUMEN

Amide-linked tripyridine derivatives 1, with a para-substituent, and 2, with a meta-substituent, were gelated in water or water-DMSO. The gelation capabilities of 1 and 2 were attributed to the cooperative effects of mainly CH-π and π-π stacking or strong intermolecular hydrogen bonding interactions between the amide groups. The fluorescence properties of gels 1 and 2 were dependent on the binding strength of the π-π stacking.

10.
J Adv Prosthodont ; 3(2): 85-9, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21814617

RESUMEN

PURPOSE: The purpose of this study was to evaluate the amount of resorption and thickness of labial bone in anterior maxillary implant using cone beam computed tomography with Hitachi CB Mercuray (Hitachi, Medico, Tokyo, Japan). MATERIALS AND METHODS: Twenty-one patients with 26 implants were followed-up and checked with CBCT. 21 OSSEOTITE NT® (3i/implant Innovations, Florida, USA) and 5 OSSEOTITE® implants (3i/implant Innovations, Florida, USA) were placed at anterior region and they were positioned vertically at the same level of bony scallop of adjacent teeth. Whenever there was no lesion or labial bone was intact, immediate placement was tried as possible as it could be. Generated bone regeneration was done in the patients with the deficiency of hard tissue using Bio-Oss® (Geistlich, Wolhusen, Switzerland) and Bio-Gide® (Geistlich, Wolhusen, Switzerland). Second surgery was done in 6 months after implant placement and provisionalization was done for 3 months. Definite abutment was made of titanium abutment with porcelain, gold and zirconia, and was attached after provisionalization. Two-dimensional slices were created to produce sagittal, coronal, axial and 3D by using OnDemand3D (Cybermed, Seoul, Korea). RESULTS: The mean value of bone resorption (distance from top of implant to labial bone) was 1.32 ± 0.86 mm and the mean thickness of labial bone was 1.91 ± 0.45 mm. CONCLUSION: It is suggested that the thickness more than 1.91 mm could reduce the amount and incidence of resorption of labial bone in maxillary anterior implant.

11.
Int Neurourol J ; 15(1): 41-7, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21468286

RESUMEN

PURPOSE: An overactive bladder (OAB) affects a person's quality of life. Patients who suffer from OAB run to the toilet frequently to prevent incontinence, and this behavior increases their risk of falling and fear of falling. This study evaluated the influence of OAB on falls and concern about falling in females aged 40 and over living in urban and rural communities. METHODS: We conducted a population-based cohort study using King's Health Questionnaire (KHQ), the Korean version of Falls Efficacy Scale-International (KFES-I) and a questionnaire regarding falls, in females aged 40 and over in Guri city and Yangpyeong county. The data from 514 responders were analyzed. The definition of OAB was 'moderately' or 'a lot' of urgency, or urge incontinence in KHQ. Falls was defined as experience of falls in the last year. High fear of falling was defined as a score of 24 or over in KFES-I. The factors were analyzed by the exact chi-square test and Student's t-test. The multivariate logistic regression model was adopted in order to examine the effects of OAB on falls and concern about falling. RESULTS: Of the 514 responders, 98 fitted the criterion of OAB. Eighty-nine (17.3%) of the responders had experienced falls in the last year: twenty-seven (27.5%) in the group with OAB and 62 (14.9%) in the group without OAB. There was a significant association between falls and OAB (odds ratio [OR], 1.76; 95% confidence interval [CI], 1.00 to 3.08; P=0.0485), and between high fear of falling and OAB (OR, 2.72; 95% CI, 1.42 to 5.20; P=0.0024). CONCLUSIONS: Urgency and symptoms of urge incontinence increase the risk of falls in women aged 40 or older in the community. Early diagnosis and proper treatment may prevent falls and improve quality of life in OAB patients.

12.
Korean J Urol ; 52(2): 150-3, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21379435

RESUMEN

The use of graft materials in bladder mucosa has been examined in animal models, but debate exists over which materials are effective. Intestine has been used as a substitute in augmentation cystoplasty for patients with neuropathic bladder, but serious adverse effects of the operation have occurred in some instances. We report a case of a successful repair of an enterovesical fistula by use of bovine pericardium. The patient has remained well for 2.5 years. We suggest that bovine pericardium may be a suitable option as a bladder substitute.

13.
Int Neurourol J ; 14(3): 186-9, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21179338

RESUMEN

Most foreign bodies in the lower genitourinary tract are self-inserted via the urethra as the result of exotic impulses, psychometric problems, sexual curiosity, or sexual practice while intoxicated. Diagnosis of these foreign bodies can be done by clinical history, physical examination, and image studies of the patient. The treatment of foreign bodies is determined by their size, location, shape, and mobility. In most cases, minimally invasive procedures such as endoscopic removal are recommended to prevent bladder and urethral injuries. In some cases, however, surgical treatment should be done if the foreign bodies cannot be removed by the endoscopic procedure or further injuries are expected as a result of the endoscopic procedures. Herein we present 2 cases of self-inserted lower genitourinary foreign bodies with a brief review of the literature.

14.
Korean J Urol ; 51(10): 677-82, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21031086

RESUMEN

PURPOSE: The Gleason score (GS) is an important factor that is considered when making decisions about prostate cancer and its prognosis. However, upgrading of the GS can occur between transrectal ultrasonography (TRUS) biopsy and radical prostatectomy. This study analyzed the clinical factors predictive of upgrading of the GS after radical prostatectomy compared with that at the time of TRUS biopsy. MATERIALS AND METHODS: We analyzed the medical records of 107 patients who had undergone radical prostatectomy. Patients were divided into two groups. Group 1 consisted of patients in whom the GS was not upgraded, and group 2 consisted of patients in whom the GS was upgraded. Associations between preoperative clinical factors and upgrading of the GS were analyzed. Preoperative clinical factors included age, prostate-specific antigen (PSA), prostate volume, PSA density, GS of TRUS biopsy, maximum core percentage of cancer, percentage of positive cores, number of biopsies, location of positive core with maximum GS, high-grade prostatic intraepithelial neplasia (HGPIN), inflammation on biopsy, and clinical stage. RESULTS: Among 85 patients, 42 (49%) patients had an upgraded GS after operation. TRUS biopsy core number of 12 or fewer (p=0.029) and prostate volume of 36.5 ml or less (p<0.001) were associated with upgrading of the GS. Preoperative clinical factors associated with nonupgrading of the GS were the detection of positive cores with a maximum GS at the apex (p=0.002) or in a hypoechoic lesion (p=0.002) in TRUS. CONCLUSIONS: If the positive cores with maximum GS are located at the apex or in a hypoechoic lesion in TRUS, we can expect that the GS will not be upgraded. In patients with the clinical predictive factors of a prostate volume of 36.5 ml or less and TRUS biopsy core number of less than 12, we can expect upgrading of the GS after radical prostatectomy, and more aggressive treatment may be needed.

15.
Korean J Urol ; 51(6): 438-40, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20577614

RESUMEN

A 26-year-old man presented with lower abdominal discomfort and a palpable mass in the right lower quadrant. An abdominal computed tomography (CT) scan revealed an abdominal wall mass that extended from the dome of the bladder. Fluorine-18 fluorodeoxyglucose (FDG) positron-emission tomography/CT (PET/CT) showed hypermetabolic wall thickening around the bladder dome area that extended to the abdominal wall and hypermetabolic mesenteric infiltration. Differential diagnosis included a urachal tumor with invasion into adjacent organs and chronic inflammatory disease. Partial cystectomy with abdominal wall mass excision was performed, and the final pathologic report was consistent with urachal actinomycosis.

16.
J Adv Prosthodont ; 1(2): 97-101, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21165262

RESUMEN

STATEMENT OF PROBLEM: Unlike screw-retention type, fixture-abutment retention in Locking taper connection depends on frictional force so it has possibility of abutment to sink. PURPOSE: In this study, Bicon® Implant System, one of the conical internal connection implant system, was used with applying loading force to the abutments connected to the fixture. Then the amount of sinking was measured. MATERIAL AND METHODS: 10 Bicon® implant fixtures were used. First, the abutment was connected to the fixture with finger force. Then it was tapped with a mallet for 3 times and loads of 20 kg corresponding to masticatory force using loading application instrument were applied successively. The abutment state, slightly connected to the fixture without pressure was considered as a reference length, and every new abutment length was measured after each load's step was added. The amount of abutment sinking (mm) was gained by subtracting the length of abutment-fixture under each loading condition from reference length. RESULTS: It was evident, that the amount of abutment sinking in Bicon® Implant System increased as loads were added. When loads of 20 kg were applied more than 5 - 7 times, sinking stopped at 0.45 ± 0.09 mm. CONCLUSION: Even though locking taper connection type implant shows good adaption to occlusal force, it has potential for abutment sinking as loads are given. When locking taper connection type implant is used, satisfactory loads are recommended for precise abutment location.

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