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We investigated the guiding of femtosecond laser pulses with an intensity of ∼1016 W/cm2 in evacuated and gas-filled glass capillaries. We measured the laser transmission versus length of two capillaries with different inner cores in a vacuum, and also the laser propagation modes in these two capillaries. We succeeded in generating an extended plasma column that was ten times longer than the Rayleigh range by propagating high-intensity femtosecond laser pulses in a gas-filled capillary. We obtained a spectral blue shift in the transmitted femtosecond laser pulses with a 5 Torr nitrogen-filled capillary and used this shift to demonstrate extended plasma column formation in a gas-filled capillary. We also measured axial soft X-ray spectra from this laser-pumped, nitrogen-filled capillary and obtained an anomalously strong emission at 45.2 nm. [Copyright &y& Elsevier]

In order to enhance a spring constant of C/C composite coil spring, the electron beam irradiation was homogeneously performed. The EB irradiation largely enhanced initial spring constants, which were higher than that before EB irradiation. The constant spring constant was also obtained by 150 Mrad-irradiation for the C/C composite coil spring. [ABSTRACT FROM AUTHOR]

1. The in vitro and in vivo metabolism of 2,4,5,2 ,4 ,5-hexachlorobiphenyl (PCB153) in guinea pig has been studied. 2. Seven metabolites were detected in the faeces of PCB153-treated animals and three were identical to those produced by dog liver microsomes. The detection of a metabolite where a chlorine atom was shifted from the 2- to 3-position strongly suggested the involvement of 2,3-arene oxide intermediate, and evidence for the concomitant formation of a 3,4-arene oxide intermediate was provided by identifying other two minor metabolites which were dechlorinated at the 4-position. 3. In vitro studies using liver microsomes from guinea pigs revealed that the 2,3-arene oxide and 3-hydroxylation pathways are the predominant metabolic routes compared with the 3,4-arene oxide pathway. Although the guinea pig is an another species that can metabolize PCB153 mainly to the 2,3-arene oxide intermediate, the rate of formation was only about one-tenth of the dog. 4. These results indicate that the ability to form this unusual 2,3-arene oxide intermediate may not be responsible for high excretion rate of this congener. Our data also suggest that the cytochrome P450-catalysed metabolism of PCB153 in the guinea pig and dog are similar, whereas for post-cytochrome P450 metabolism, the guinea pig resembles the rabbit. [ABSTRACT FROM AUTHOR]

1. The cytochrome P450 isozymes involved in the deamination of amphetamine (AP) andbenzphetamine (BZP) have been studied in liver microsomes from rabbit and rat using isozyme-specific inhibitors. 2. Metabolism ofBZP in ratyielding phenylacetone and formaldehyde was moderately inhibited by testosterone and chloramphenicol. N -Debenzylation was thought tobe P450- dependent, but all inhibitors except for a non-specific inhibitor, SKF-525A, failed to inhibit this reaction. 3. In rabbit, quinidine and testosterone were potent inhibitors of both BZP de amination and dealkylation. Deamination of AP in rabbit was extensively inhibited only with quinidine. 4. AP eamination with purified rabbit CYP2C3, which was previously identified as the major isozyme responsible for this metabolism, was extensively inhibited with quinidine, previously thought to be a specific inhibitor of CYP2D. 5. These results strongly support the notionthatthe CYP2C isozymes playamajorrole in the deamination of both AP and BZP, but not for N -debenzylation of BZP in rat. However, on the basis of different sensitivities toward inhibitors, multiple isozymes seem to be involved in BZP deaminations in both species. [ABSTRACT FROM AUTHOR]

A thorough understanding of the stability of graphene under ambient environmental conditions is essential for future graphene-based applications. In this paper, we study the effects of ambient temperature on the properties of monolayer graphene using terahertz time-domain spectroscopy as well as time-resolved terahertz spectroscopy enabled by an optical-pump/terahertz-probe technique. The observations show that graphene is extremely sensitive to the ambient environmental conditions and behaves differently depending on the sample preparation technique and the initial Fermi level. The analysis of the spectroscopic data is supported by van der Pauw and Hall effect measurements of the carrier mobility and carrier density at temperatures comparable to those tested in our THz spectroscopic experiments. [ABSTRACT FROM AUTHOR]

Symmetries essentially provide conservation rules in nonlinear light-matter interactions and facilitate control and understanding of photon conversion processes or electron dynamics. Since anisotropic solids have rich symmetries, they are strong candidates for controlling both optical micro- and macroscale structures, namely, spin angular momentum (circular polarization) and orbital angular momentum (spiral wavefront), respectively. Here, we show structured high-harmonic generation linked to the anisotropic symmetry of a solid. By strategically preserving a dynamical symmetry arising from the spin-orbit interaction of light, we generate multiple orbital angular momentum states in high-order harmonics. The experimental results exhibit the total angular momentum conservation rule of light even in the extreme nonlinear region, which is evidence that the mechanism originates from a dynamical symmetry. Our study provides a deeper understanding of multiscale nonlinear optical phenomena and a general guideline for using electronic structures to control structured light, such as through Floquet engineering.

Background: It is unclear witch regimen is optimal as salvage chemotherapy (SCT) after immune checkpoint inhibitor (ICI) monotherapy for recurrent or metastatic head and neck cancer (RM-HNC)., Methods: This study enrolled 109 patients. Overall survival (OS) and progression-free survival 2 (PFS2) were compared between patients stratified by SCT regimen., Results: Of the 109 patients, 55 underwent SCT after the failure of ICI monotherapy. The OS of these 55 patients was longer than that of patients who did not undergo SCT. The OS and PFS2 were similar between patients treated with paclitaxel (PTX) and cetuximab (Cmab) combination and those treated with PTX monotherapy. The occurrence of irAEs did not impact PFS2 nor OS., Conclusions: SCT can improve the survival outcomes of patients with RM-HNC. In addition to PTX and Cmab, PTX monotherapy is also considered an effective SCT regimen. SCT is effective regardless of the presence or absence of irAEs., (© 2024 Wiley Periodicals LLC.)

The hadopelagic environment remains highly understudied due to the inherent difficulties in sampling at these depths. The use of sediment environmental DNA (eDNA) can overcome some of these restrictions as settled and preserved DNA represent an archive of the biological communities. We use sediment eDNA to assess changes in the community within one of the world's most productive open-ocean ecosystems: the Atacama Trench. The ecosystems around the Atacama Trench have been intensively fished and are affected by climate oscillations, but the understanding of potential impacts on the marine community is limited. We sampled five sites using sediment cores at water depths from 2400 to ~8000 m. The chronologies of the sedimentary record were determined using 210 Pb ex . Environmental DNA was extracted from core slices and metabarcoding was used to identify the eukaryote community using two separate primer pairs for different sections of the 18S rRNA gene (V9 and V7) effectively targeting pelagic taxa. The reconstructed communities were similar among markers and mainly composed of chordates and members of the Chromista kingdom. Alpha diversity was estimated for all sites in intervals of 15 years (from 1842 to 2018), showing a severe drop in biodiversity from 1970 to 1985 that aligns with one of the strongest known El Niño events and extensive fishing efforts during the time. We find a direct impact of sea surface temperature on the community composition over time. Fish and cnidarian read abundance was examined separately to determine whether fishing had a direct impact, but no direct relation was found. These results demonstrate that sediment eDNA can be a valuable emerging tool providing insight in historical perspectives on ecosystem developments. This study constitutes an important step toward an improved understanding of the importance of environmental and anthropogenic drivers in affecting open and deep ocean communities., (Global Change Biology© 2024 The Author(s). Global Change Biology published by John Wiley & Sons Ltd.)

Understanding microplastic (MP) behavior in oceans is crucial for reducing marine plastic pollution. However, the complex process underlying MP transportation to the deep seafloor remains unknown despite the deep sea being considered its major sink. We focused on MP distribution in Sagami Bay (adjacent to highly populated areas of Japan), the plate triple junction connected through the Sagami Trough, and the abyssal plain immediately below the Kuroshio Extension. We observed the highest number of MPs in the abyssal stations, more than previously reported. The polymer types and aspect ratio of MPs in the abyssal stations significantly differed from those in the bathyal/hadal stations. The study suggests that MPs accumulated in the open ocean surface layer sink to the abyssal plains immediately below it, while MPs from land sources accumulate in the bathyal depth and are transported to the hadal depth near the coast through turbidity currents along the submarine canyon., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Acoustically induced dressed states of long-lived erbium ions in a crystal are demonstrated. These states are formed by rapid modulation of two-level systems via strain induced by surface acoustic waves whose frequencies exceed the optical linewidth of the ion ensemble. Multiple sidebands and the reduction of their intensities appearing near the surface are evidence of a strong interaction between the acoustic waves and the ions. This development allows for on-chip control of long-lived ions and paves the way to highly coherent hybrid quantum systems with telecom photons, acoustic phonons, and electrons.

Background: We aimed to define the indications for sentinel lymph node biopsy (SLNB), the third option for cervical treatment in oral cancer with negative cervical lymph nodes., Methods: The greatest depth of invasion (DOI) and long diameter (LD) of the primary site were used as exposures. SLN metastasis was considered the outcome., Results: In three trials conducted between 2009 and 2016, 158 patients were eligible and reassigned to this study group. The scatterplot based on the respective values of DOI and LD would eventually be divided into three sections. In cases of sections T1, T2, and T3, the proportions of SLN metastasis positivity were 21.3%, 35.3%, and 51.2%, respectively. In certain cases of T1 with 2 mm < DOI ≤ 5 mm and 8 mm < LD ≤ 20 mm, the proportion of SLN metastasis positivity was 40.9%., Conclusions: SLNB-navigated or assisted neck dissection can be added as an effective procedure for N0 neck control., (© 2023 Wiley Periodicals LLC.)

The accumulation of polybrominated diphenyl ethers (PBDEs) and benzotriazole UV stabilizers (BZT-UVs) were examined in the hadal amphipod Hirondellea gigas caught from a near-land trench off the Japan island (9200 m). H. gigas were collected from two distinct sites: one is located at the outlet of submarine canyons directly connected to land and the other is apart from the outlet and geographically isolated from the first site. The level of the PBDEs in H. gigas at the canyon outlet (mean 219 ng/g lipid weight (l.w.)) was significantly higher than that in the isolated site (mean 42 ng/g l.w.) and BZT-UVs were only detected within the first site (mean 1.5 ng/g wet weight). In addition to vertical transport from the surface water, near-land trenches associated with submarine canyons and troughs may have more complex influx of contaminants through horizontal transportation from the land, resulting in more severe contamination., Competing Interests: The authors declare no competing interests., (© 2023 The Author(s).)

A simpler and more accurate measurement of absolute optical frequencies (AOFs) is very important for optical communications and navigation systems. To date, an optical reference has been needed for measuring AOFs with twelve-digit accuracy because of the difficulty in measuring them directly. Here, we focus on an electro-optics-modulation comb that can bridge the vast frequency gap between photonics and electronics. We demonstrate an unprecedented method that can directly measure AOFs to an accuracy of twelve digits with an RF frequency counter by simply delivering a frequency-unknown laser into an optical phase modulator. This could open up a new horizon for optical-referenceless optical frequency metrology. Our method can also simultaneously achieve a 100-fold phase-noise reduction in a conventional signal generator. This corresponds to an increase in the transmission speed of wireless communications of by about seven times., (© 2023. The Author(s).)

We generate 1.7-cycle and 35-µJ pulses at a 1-MHz repetition rate by using two-stage multiple plate continuum compression of Yb-laser pulses with 80-W average input power. By adjusting the plate positions with careful consideration of the thermal lensing effect due to the high average power, we compress the output pulse with a 184-fs initial duration to 5.7 fs by using only group-delay-dispersion compensation. This pulse achieves a sufficient beam quality (M 2  < 1.5) reaching a focused intensity over 10 14 W/cm 2 and a high spatial-spectral homogeneity (98%). Our study holds promise for a MHz-isolated-attosecond-pulse source for advanced attosecond spectroscopic and imaging technologies with unprecedentedly high signal-to-noise ratios.

This sentinel node (SN) biopsy trial aimed to assess its effectiveness in identifying predictive factors of micrometastases and to determine whether elective neck dissection is necessary in oral squamous cell carcinoma. This retrospective study included 55 patients from three previous trials, with positive SNs. The relationship between the sizes of the metastatic focus and metastasis in non-sentinel node (NSN) was investigated. Four of the 55 largest metastatic focus were isolated tumor cells, and the remaining 51 were ranged from 0.2 to 15 mm, with a median of 2.6 mm. The difference of prevalence between 46 negative- and 9 positive-NSN was statistically significant with regard to age, long diameter of primary site and number of cases with regional recurrence. In comparing the size of largest metastatic focus dividing the number of positive SN, with metastaic focus range of < 3.0 mm in one-positive SN group, there were 18 (33%) negative-NSN and no positive-NSN. Regarding prognosis, 3-year overall survival rate of this group (n = 18) and other (n = 37) were 94% and 73% (p = 0.04), and 3-year recurrence free survival rate of this group and other were 94% and 51% (p = 0.03), respectively. Absolutely a further prospective clinical trial would be needed, micrometastases may be defined as solitary SN metastasis with < 3.0 mm of metastatic focus, and approximately 33% of neck dissections could be avoided using these criteria., (© 2023. The Author(s).)

Burial of persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs) in deep-sea sediments contributes to 60% of their historical emissions. Yet, empirical data on their occurrence in the deep-ocean is scarce. Estimates of the deep-ocean POP sink are therefore uncertain. Hadal trenches, representing the deepest part of the ocean, are hotspots for organic carbon burial and decomposition. POPs favorably partition to organic carbon, making trenches likely significant sinks for contaminants. Here we show that PCBs occur in both hadal (7720-8085 m) and non-hadal (2560-4050 m) sediment in the Atacama Trench. PCB concentrations normalized to sediment dry weight were similar across sites while those normalized to sediment organic carbon increased exponentially as the inert organic carbon fraction of the sediment increased in degraded hadal sediments. We suggest that the unique deposition dynamics and elevated turnover of organic carbon in hadal trenches increase POP concentrations in the deepest places on Earth., (© 2023. The Author(s).)

We propose a method of supercontinuum light generation enhanced by multimode excitation in a precisely dispersion-engineered deuterated SiN (SiN:D) waveguide. Although a regularly designed SiN-based nonlinear optical waveguide exhibits anomalous dispersion with the fundamental and first-order multimode operation, the center-symmetric light pumping at the input edge has so far inhibited the full potential of the nonlinearity of SiN-based materials. On the basis of numerical analysis and simulation for the SiN:D waveguide, we intentionally applied spatial position offsets to excite the fundamental and higher-order modes to realize bandwidth broadening with flatness. Using this method, we achieved an SNR improvement of up to 18 dB at a wavelength of 0.6 µm with an offset of about 1 µm in the Y-axis direction and found that the contribution was related to the presence of dispersive waves due to the excitation of TE 10 , and TE 01 modes.

Immune checkpoint inhibitors (ICIs) have become the standard treatment for recurrent or metastatic head and neck cancer (RM-HNC). However, many patients fail to benefit from the treatment. Previous studies have revealed that tumor burden predicts the efficacy of ICIs, but this association remains unclear for RM-HNC. We retrospectively analyzed 94 patients with RM-HNC treated with ICI monotherapy. We estimated the tumor burden using the baseline number of metastatic lesions (BNML) and the baseline sum of the longest diameters of the target lesions (BSLD), and evaluated the association between BNML, BSLD, and standardized uptake value (SUV) and clinical outcomes. The median progression-free survival (PFS) was 7.1 and 3.1 months in the low-BNML and high-BNML groups, respectively (p = 0.010). The median PFS was 9.1 and 3.5 months in the low-BSLD and high-BSLD groups, respectively (p = 0.004). Moreover, patients with high SUVmax levels had worse overall survival (OS) and PFS. BNML, BSLD, and SUVmax are useful prognostic factors in patients with RM-HNC treated with ICIs. Imaging examinations before ICI treatment are recommended to predict the efficacy of ICIs. If the tumor burden is high, cytotoxic anticancer agents may be administered concomitantly with or prior to ICI monotherapy., (© 2022. The Author(s).)

Submergence during germination impedes aerobic metabolisms and limits the growth of most higher plants. However, some wetland plants including rice can germinate under submerged conditions. It has long been hypothesized that the first elongating shoot tissue, the coleoptile, acts as a snorkel to acquire atmospheric oxygen (O 2 ) to initiate the first leaf elongation and seminal root emergence. Here, we obtained direct evidence for this hypothesis by visualizing the spatiotemporal O 2 dynamics during submerged germination in rice using a planar O 2 optode system. In parallel with the O 2 imaging, we tracked the anatomical development of shoot and root tissues in real-time using an automated flatbed scanner. Three hours after the coleoptile tip reached the water surface, O 2 levels around the embryo transiently increased. At this time, the activity of alcohol dehydrogenase (ADH), an enzyme critical for anaerobic metabolism, was significantly reduced, and the coleorhiza covering the seminal roots in the embryo was broken. Approximately 10 h after the transient burst in O 2 , seminal roots emerged. A transient O 2 burst around the embryo was shown to be essential for seminal root emergence during submerged rice germination. The parallel application of a planar O 2 optode system and automated scanning system can be a powerful tool for examining how environmental conditions affect germination in rice and other plants., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Shiono, Koshide, Iwasaki, Oguri, Fukao, Larsen and Glud.)

We have achieved the simultaneous generation of a 2.6-octave-wide supercontinuum (SC) spectrum over 400-2500 nm and third-harmonic light solely by a dispersion-controlled silicon-nitride waveguide (SiNW). To increase the visible intensity of the SC light component, we fabricated low-loss 5-mm-long deuterated SiNWs with spot-size converters by low-temperature deposition. We succeeded in measuring the carrier-envelope-offset (CEO) signal with a 34-dB signal-to-noise ratio because this short deuterated SiNW provides a large temporal overlap between the f and 3f components. In addition, we have demonstrated this method of CEO locking at telecommunications wavelengths with f-3f self-referencing generated solely by the SiNW without the use of highly nonlinear fiber and an additional nonlinear crystal. Compared with the method of CEO locking with a highly nonlinear fiber and a standard f-2f self-referencing interferometer, this method is not only simple and compact but also stable.