Frequency resolution improvement by sub-bins and an inverse matrix in discrete Fourier transform.

We proposed a method to use sub-bins (SBs) and the inverse matrix to reduce the spectral leakage in discrete Fourier transform (DFT) over the conventional spectral resolution. SBs were assigned between two conventional bins. Utilizing the real signal, the process reproducing complex amplitudes at each SB was described and confirmed through simulations with the pseudo-inverse matrix. In experiments, with the 256 number of data, the frequency interval of k=107 and 108 was 4 divided by SBs. The single-peak spectrum at each SB frequency was measured clearly. Using the two signals with frequencies corresponding to two SBs within the conventional bin interval, the spectrum with two peaks was also measured. The linearity was confirmed for the input range from 0.1-5 V. The feasibility of this method to improve the frequency resolution has been shown for various optical applications.

[Stanford Type B Acute Aortic Dissection Complicated by Lower Limb Ischemia Late after Abdominal Aortic Graft Replacement].

Leg ischemia is a serious complication of acute aortic dissection. Few cases of lower extremity ischemia due to dissection late after abdominal aortic graft replacement have been reported. Critical limb ischemia occurs when true lumen blood flow is obstructed by the false lumen at the proximal anastomosis of the abdominal aortic graft. Usually, the inferior mesenteric artery (IMA) is reimplanted to the aortic graft to avoid intestinal ischemia. We therein report a case of Stanford type B acute aortic dissection, in which previously reimplanted IMA prevented bilateral lower extremity ischemia. A 58-years-old male with a history of abdominal aortic replacement experienced sudden onset of epigastralgia and subsequent pain in the back and the right lower limb and was admitted to the authors' hospital. Computed tomography (CT) revealed Stanford type B acute aortic dissection, and occlusion of the abdominal aortic graft, and the right common iliac artery. However, the left common iliac artery was perfused through the reconstructed IMA during previous abdominal aortic replacement. The patient underwent thoracic endovascular aortic repair and thrombectomy, and had an uneventful recovery. For residual arterial thrombi in the abdominal aortic graft, oral warfarin potassium was administered for 16 days until the day of discharge. Since then, the thrombus has dissolved and the patient has been doing well without any lower extremity disorders.

[Successful Surgical Correction of Partial Atrioventricular Septal Defect in an Elderly Patient:Report of a Case].

There are only few reports on surgery for partial atrioventricular septal defect( pAVSD) in patients aged over 70 years. This report is about successful surgical correction of pAVSD in a 79-year-old women. Echocardiography showed left-sided atrioventricular valve regurgitation with cleft and ostium primum atrial septal defect, but without ventricular septal defect. Accordingly, she was diagnosed with pAVSD. Treatment plan included direct cleft closure, patch closure for the ostium primum atrial septal defect, and right atrioventricular annuloplasty. The postoperative course was uneventful. She was followed up without complications for four years. To the best of our knowledge, our patient is the oldest to undergo such surgical techniques in Japan to date.

Improvement of frequency resolution using a sub-bin structure in the discrete Fourier transform.

To improve frequency resolution, assignments of sub-bins within the bin interval of the conventional discrete Fourier transform are proposed by decreasing the number of sampled data. The simulated and experimental results of the basic sub-bin spectrum characteristics are presented. Using a signal oscillator, digital oscilloscope, and PC, the sub-bin line spectrum between two conventional bins is measured, and nine line spectra of sub-bins corresponding to the simulated results are measured. The linearity of the sub-bin spectrum intensity for amplitudes of 0.001-10 V of the input signal is also measured. The Doppler signals from the optical interferometer using a He-Ne laser are measured using a mixer to tune the frequency. A sub-bin spectrum of 104.89 kHz between two bin frequencies of 104.49 and 105.47 kHz is measured using 256 data points at a sampling frequency of 250 kHz and an acquisition time of 1.024 ms. The precision of displacement for the acquisition time is improved by one order to 32 nm for a full displacement of 2.342 µm. The sub-bins, as a composition of bin structure, are applicable to various fields.

[Double Patch Closure for Ruptured Sinus of Valsalva Aneurysm:Report of a Case].

A 53-year-old man visited a previous hospital because of dyspnea. He was transferred to our hospital with a diagnosis of a ruptured Valsalva aneurysm. At surgery, the tip of aneurysm originated from the right sinus of Valsalva had ruptured into the right ventricular outflow tract. A longitudinal incision was made in the main pulmonary artery, and the rupture site was closed with continuous suture. The first Hemashield patch was sewn to the tissue around the aneurysm in the right ventricular outlet septum. After that, the second Hemashield patch was fixed to the patch of the right ventricular outlet septum by horizontal mattress suture from the aorta. There has been no problem for more than five years after surgery.

Frequency-agile injection-seeded terahertz-wave parametric generation: publisher's note.

This publisher's note contains corrections to Opt. Lett.45, 77 (2020)OPLEDP0146-959210.1364/OL.45.000077.

Differential phase imaging in full-field optical coherence microscopy using a short multimode fiber probe.

We demonstrate phase imaging that reduces the common phase noise in full-field optical coherence microscopy using a short multimode fiber (SMMF) probe. Using a cover glass, phase images of the SMMF and sample surfaces were measured simultaneously. Subtracting the phase of the SMMF surface as a reference, the phase drifts in the sample region are reduced. The axial and lateral resolutions were 2.3 µm and <4.4µm, respectively. The standard deviation of the time variation in the phase decreased from 14.3 deg to 9.2 deg and was reduced by 64% when in contact with the polymer film at the SMMF. In quantitative evaluations, the measured phases closely correspond to the phases changed by a piezoelectric device.

Cyclic Sulfamidite as Simultaneous Protecting Group for Amino Alcohols: Development of a Mild Deprotection Protocol Using Thiophenol.

This study describes the novel utility of cyclic sulfamidite as a simultaneous protecting group for 1,2- or 1,3-amino alcohols. An exceptionally mild and neutral condition for the removal of the cyclic sulfamidite was developed. The deprotection condition demonstrated a broad range of functional-group compatibility, including a substrate bearing a Z-enyne structure without any loss of double-bond stereochemistry.

The timing of cumulus cell removal for intracytoplasmic sperm injection influences the capability of embryonic development.

PURPOSE: To determine whether the presence of intact cumulus cells during the preincubation period for ICSI should be considered as a critical factor in fertilization and embryonic development. METHODS: The cohort of this prospective randomized study was limited to infertile women younger than 39 years of age who underwent controlled ovarian stimulation for ICSI between October 2013 and May 2015 and whose embryos were to be incubated until day 5. Women with estradiol levels of <2000 pmol/L on the day of HCG injection were excluded. Cumulus cells were removed immediately after OPU in Group A and at 120 minutes after OPU in Group B. ICSI was performed with all mature oocytes, and fertilized oocytes were cultured to the blastocyst stage. Maturation, fertilization, blastocyst, good quality blastocyst, pregnancy, live birth, and miscarriage rates were compared. RESULTS: There were no significant differences in maturation, fertilization, blastocyst, pregnancy, live birth, or miscarriage rates between Groups A and B. However, the percentage of good quality blastocysts was significantly higher in Group B than Group A (52.0% vs 33.1%). CONCLUSIONS: Intact cumulus cells should be maintained during the preincubation period, as they are important to embryonic development after fertilization.

[Mycotic Aneurysm of the Ulnar Artery Associated with Infective Endocarditis;Report of a Case].

A 19-year-old man, with a history of hospitalization for infective endocarditis associated with Streptococcus mitis/oralis 2 months before, was admitted to our hospital because of stomach ache and pulsatile mass on the left forearm. Computed tomography(CT) and ultrasonography revealed a thrombus in the superior mesenteric artery and an aneurysm of the left ulnar artery. As vegetation was noted on the anterior leaflet of the mitral valve, mitral valve replacement and ulnar artery aneurysmorrhaphy were performed. He was discharged 24 days after surgery without any complications. Although mycotic aneurysm is one of the complications of infective endocarditis, it is rarely formed in the ulnar artery. Moreover, mycotic aneurysm may develop even after inflammatory reaction has subsided. Thus, longterm observation of patients with infective endocarditis is necessary.

Depolarization characteristics of spatial modes in imaging probe using short multimode fiber.

Optical coherence tomography is one of the standard imaging modalities at present, widely used in the medical and biological fields to obtain three-dimensional (3D) images with high spatial resolution. However, the depth up to which the 3D images can be directly obtained is limited to within 3 mm. Therefore, the suitability of many kinds of catheters and needles has been considered for minimally invasive imaging. We have examined the utility of a short multimode fiber (SMMF) using graded index optical fibers for minimal invasive imaging of deeper areas, up to 6-8 mm. The diameter and length of the SMMF are 125 µm and 6-8 mm, respectively. In the core of the SMMF, scattering and multirefraction occur due to small variations in the refractive index to generate deformations and depolarization of images. In order to investigate the depolarization characteristics, the images reflected at the facet of the SMMF were measured by changing the angle of the polarizer, using an LED as the light source. The reflection image almost corresponds to that obtained with combined linearly polarized modes with the ratio of LP01∶LP11∶LP21 equal to 1∶0.2∶0.7. Comparing the measured results with simulations in the simple model, the depolarization ratio was estimated at 0.7 in the core. The degrees of polarization were measured to be 0.15 around the center and increased to 0.90 at the periphery.

Gamma Knife Radiosurgery for Metastatic Brain Tumors from Malignant Melanomas: A Japanese Multi-Institutional Cooperative and Retrospective Cohort Study (JLGK1501).

BACKGROUND: The incidences of metastatic brain tumors from malignant melanomas have increased and survival has been prolonged by novel molecular targeted agents and immunotherapy. However, malignant melanomas are uncommon in Asian populations. OBJECTIVES: We retrospectively analyzed treatment efficacy and identified prognostic factors impacting tumor control and survival in Japanese melanoma patients with brain metastases treated with gamma knife radiosurgery (GKRS). METHODS: We retrospectively reviewed the medical records of 177 patients with 1,500 tumors who underwent GKRS for brain metastases from malignant melanomas. This study was conducted by the Japanese Leksell Gamma Knife Society (JLGK1501). RESULTS: Six and 12 months after GKRS, the cumulative incidences of local tumor recurrence were 9.2 and 13.8%. Intratumoral hemorrhage (p < 0.0001) and larger tumor volume (p = 0.001) in GKRS were associated with significantly poorer local control outcomes. The use of immune checkpoint inhibitors before GKRS was significantly associated with symptomatic adverse events (p = 0.037). The median overall survival time after the initial GKRS was 7.3 months. Lower Karnofsky performance status scores (p = 0.016), uncontrolled primary cancer (p < 0.0001), and multiple brain metastases (p = 0.014) significantly influenced unfavorable overall survival outcomes. The cumulative incidences of neurological death 6 and 12 months after GKRS were 9.7 and 17.4%, those of neurological deterioration were 14.2 and 19.6%, and those of new tumor appearance were 34.5 and 40.5%. CONCLUSIONS: The results of the present multicenter study suggest that GKRS is a relatively effective and safe modality for control of tumor progression in Japanese patients with brain metastases from malignant melanomas.

In Vivo Evaluation of Cerebral Hemodynamics and Tissue Morphology in Rats during Changing Fraction of Inspired Oxygen Based on Spectrocolorimetric Imaging Technique.

During surgical treatment for cerebrovascular diseases, cortical hemodynamics are often controlled by bypass graft surgery, temporary occlusion of arteries, and surgical removal of veins. Since the brain is vulnerable to hypoxemia and ischemia, interruption of cerebral blood flow reduces the oxygen supply to tissues and induces irreversible damage to cells and tissues. Monitoring of cerebral hemodynamics and alteration of cellular structure during neurosurgery is thus crucial. Sequential recordings of red-green-blue (RGB) images of in vivo exposed rat brains were made during hyperoxia, normoxia, hypoxia, and anoxia. Monte Carlo simulation of light transport in brain tissue was used to specify relationships among RGB-values and oxygenated hemoglobin concentration (CHbO), deoxygenated hemoglobin concentration (CHbR), total hemoglobin concentration (CHbT), hemoglobin oxygen saturation (StO2), and scattering power b. Temporal courses of CHbO, CHbR, CHbT, and StO2 indicated physiological responses to reduced oxygen delivery to cerebral tissue. A rapid decrease in light scattering power b was observed after respiratory arrest, similar to the negative deflection of the extracellular direct current (DC) potential in so-called anoxic depolarization. These results suggest the potential of this method for evaluating pathophysiological conditions and loss of tissue viability.

Potential risk factors for postoperative complications and deaths after laparoscopic cholecystectomy in the elderly.

Laparoscopic cholecystectomy (LC) is performed for gallbladder stones and cholecystitis in a large number of elderly patients. However, the safety of LC in the elderly is questioned. The aim of this study was to investigate predictive factors for the incidence of postoperative complications and deaths after LC in patients aged 80 years and older. Data from 85 elderly patients who underwent LC between January 2005 and December 2015 were prospectively collected in a database at our hospital. The following factors were compared for the occurrence of postoperative complications and deaths:age, gender, Body Mass Index, laboratory date, severity grade of cholecystitis, comorbidity of choledocholithiasis, conversion to open cholecystectomy, early or delayed LC, amount of time from onset to LC, operative duration, blood loss, and the following scoring systems for predicting risk of surgery:ECOG-PS, ASA, SIRS, CONUT, POSSUM, SAS, E-PASS. The complication rate of LC was 14.1% in this cohort. WBC, CRP, BUN, Cre, Na, PT-INR, severity of cholecystitis, conversion to open cholecystectomy, operative duration, early LC, ASA, SIRS, CONUT, POSSUM (PS, OS, complication rate), SAS, E-PASS (PRS, SSS, CRS) showed significant variability in univariate analysis. A high POSSUM score of complication and moderate or severe cholecystitis were independent risk factors for postoperative complication. Analysis of the ROC showed that the best cut-off point for the POSSUM score of complication was 51.5. LC for gallbladder stones and cholecystitis in elderly is a reliable operation, but the procedure for cases with a high score of the POSSUM for complications, or moderate or severe cholecystitis, may have the risk of postoperative complications in elderly patients.

Total Synthesis of (-)-Histrionicotoxin through a Stereoselective Radical Translocation-Cyclization Reaction.

Stereoselective total syntheses of (-)-histrionicotoxin and (-)-histrionicotoxin 235A are described. The 1-azaspiro[5.5]undecane skeleton was constructed diastereoselectively by a radical translocation-cyclization reaction involving a chiral cyclic acetal; the use of tris(trimethylsilyl)silane was crucial for the high diastereoselectivity. The cyclization product was converted into (-)-histrionicotoxin 235A through a one-pot partial-reduction-allylation reaction of a derivative containing an unprotected lactam. Finally, two terminal alkenes were transformed into enynes with the 1,3-amino alcohol protected as an oxathiazolidine oxide to complete the total synthesis of (-)-histrionicotoxin.

Symmetric 4,4'-(piperidin-4-ylidenemethylene)bisphenol derivatives as novel tunable estrogen receptor (ER) modulators.

We designed and synthesized 4,4'-(piperidin-4-ylidenemethylene)bisphenol derivatives as novel tunable estrogen receptor (ER) modulators. The introduction of hydrophobic substituents on the nitrogen atom of the piperidine ring enhanced ERα binding affinity. In addition, the introduction of four methyl groups adjacent to the piperidine ring nitrogen atom remarkably enhanced ERα binding affinity. N-Acetyl-2,2,6,6-tetramethylpiperidine derivative 3b showed high ERα binding affinity, high MCF-7 cell proliferation inducing activity, and high metabolic stability in rat liver S9 fractions.

Imaging characteristics of an 8.8 mm long and 125 µm thick graded-index short multimode fiber probe.

We demonstrated the feasibility of an ultrathin imaging probe with a 50-µm core diameter, a 125 µm total diameter, and an 8.8 mm length, which is a typical graded-index multimode fiber for optical communications. We used an ABCD matrix to analyze the imaging conditions and magnification, which corresponded closely to the measured results. The lateral resolution was calculated at 1.2 µm with a wavelength of 730 nm, which reflects the image test pattern where a period of 4.38 µm was measured with a wavelength of 730 nm. In the numerical aperture of the objective lens, we experimentally evaluated the tradeoff between the magnification and the coupling efficiency. At four wavelengths of 540 nm, 632 nm, 730 nm, and 852 nm, the contrast and signal intensity versus the wavelength were investigated to show that the contrast at 632 and 730 nm is relatively high. By using a thin random phase screen model, we explained that as the wavelength decreases the greater the decrease in the optical transfer function at higher spatial frequencies. Using a 635 nm LED light source, we imaged the surfaces of chicken tendons in contact and the surface roughness was visible.

Estrogenic activity of bis(4-hydroxyphenyl)methanes with cyclic hydrophobic structure.

Monoalkylated bis(4-hydroxyphenyl)methanes (e.g., 1) are reported to show weak binding affinity for estrogen receptor (ER). We hypothesized that introduction of appropriately located hydrophobic substituents in these compounds would increase the binding affinity. Indeed, we found that bis(4-hydroxyphenyl)methane bearing a 3,3-dimethylcyclohexyl group (7) shows potent ERα binding affinity, comparable to that of estradiol. Bulkier substituents could be introduced at the 3,3-position without decreasing the affinity. However, the position of the substituents was critical: the 4,4-dimethylcyclohexyl derivative (2) showed very weak binding affinity. The compounds with high ER-binding affinity showed predominantly agonistic activity, together with weak antagonistic activity at high concentration, in cell proliferation assay with human breast cancer cell line MCF-7. Further structure-function studies of these compounds and their derivatives might lead to the development of more selective and potent estrogen receptor modulators.

[Clinical effects of tolvaptan for patients with stage 4-5 chronic kidney disease in cardiac surgery].

We report clinical effects of tolvaptan, a vasopressin V2 receptor antagonist, in cardiac surgery. Tolvaptan was administrated to 5 patients with non-dialysis dependent stage 4-5 chronic kidney disease (CKD) during an early postoperative stage. Tolvaptan increased urine output and improved respiratory function in all patients without causing hemodynamic deterioration. All patients were able to avoid initiating long-term hemodialysis during hospital stay. Tolvaptan was effective and safe after cardiac surgery for patients with severe CKD.

[Bilateral congenital coronary-pulmonary artery fistulas; report of a case].

Bilateral coronary-pulmonary artery fistulas are very rare. We report a case of a 68-year-old woman without any previous medical history, who presented to our hospital after slow onset of chest heaviness on exertion. Coronary computed tomography (CT) and angiography revealed 2 fistulas:one arising from the left anterior descending artery accompanied by an aneurysm and the other from the right coronary artery. We opened the trunk of the pulmonary artery under cardio-pulmonary bypass and cardiac arrest. We recognized the outflow of the shunt just above the right pulmonary cusp, which was closed from the outside. We also closed the aneurysm of the shunt. Neither the fistulas nor the aneurysm was recognized by postoperative CT. The chest symptom disappeared.