MultiSite Gateway Technology Is Useful for Donor DNA Plasmid Construction in CRISPR/Cas9-Mediated Knock-In System

The clustered regulatory interspaced short palindromic repeats (CRISPR)/Cas9 method is a powerful tool for genome editing, by introducing a DNA double-strand break (DSB) at the specific site. The gene knock-out can be achieved by the deletion or insertion at the CRISPR/Cas9-mediated DSB site by error-prone nonhomologous end joining repair in targeted cells. However, the gene knock-in is still difficult as compared to the knock-out, because of the low efficiency of homology directed repair with donor DNA in cells. Therefore, to efficiently select the knock-in cells, we developed a complicated donor DNA plasmid containing an antibiotic-resistance gene, in addition to the knock-in sequence and the two homology arms. MultiSite Gateway technology is a useful tool for constructing this complicated plasmid. We describe the MultiSite Gateway technology and provide an overview of the DSB repair pathways to clarify the knock-out and knock-in methods by the CRISPR/Cas9 system

Delay Time Distribution Measurement of Type Ia Supernovae by the Subaru/XMM-Newton Deep Survey and Implications for the Progenitor

The delay time distribution (DTD) of type Ia supernovae (SNe Ia) from star formation is an important clue to reveal the still unknown progenitor system of SNe Ia. Here we report on a measurement of the SN Ia DTD in a delay time range of t_Ia = 0.1-8.0 Gyr by using the faint variable objects detected in the Subaru/XMM-Newton Deep Survey (SXDS) down to i' ~ 25.5. We select 65 SN candidates showing significant spatial offset from nuclei of the host galaxies having old stellar population at z ~ 0.4-1.2, out of more than 1,000 SXDS variable objects. Although spectroscopic type classification is not available for these, we quantitatively demonstrate that more than ~80% of these should be SNe Ia. The DTD is derived using the stellar age estimates of the old galaxies based on 9 band photometries from optical to mid-infrared wavelength. Combined with the observed SN Ia rate in elliptical galaxies at the local universe, the DTD in t_Ia ~ 0.1-10 Gyr is well described by a featureless power-law as f_D(t_Ia) \propto t_Ia^{-1}. The derived DTD is in excellent agreement with the generic prediction of the double-degenerate scenario, giving a strong support to this scenario. In the single-degenerate (SD) scenario, although predictions by simple analytic formulations have broad DTD shapes that are similar to the observation, DTD shapes calculated by more detailed binary population synthesis tend to have strong peaks at characteristic time scales, which do not fit the observation. This result thus indicates either that the SD channel is not the major contributor to SNe Ia in old stellar population, or that improvement of binary population synthesis theory is required. Various sources of systematic uncertainties are examined and tested, but our main conclusions are not affected significantly.Comment: Matches the final version to be published in PASJ. A very minor bug in the visibility time calculation has been fixed, resulting in slight changes in the derived DTD (<~ 10%). Conclusions are not affected at all. The font error of the labels in Fig 3 also fixe

Benign Adult Familial Myoclonic Epilepsy (BAFME)

Fourteen of the 26 members of two families with hereditary myoclonic epilepsy were studied, and the following findings were obtained. The disease was transmitted by autosomal dominant inheritance, and the onset was observed after adolescence with tremulous finger movement and/or myoclonus of the extremities. The clinical course was nonprogressive and neither dementia nor cerebellar ataxia developed during observation of over 10 years. The myoclonus appeared predominantly in the four extremities, not only at rest but also on posturing or in action, and it was increased by fatigue, insomnia or photic stimulations. Epileptic seizures appeared in 12 patients, though the frequency of seizures was relatively rare. Usually, increased diffuse myoclonic jerks were followed by generalized tonic-clonic convulsions. Electroencephalograms showed generalized spikes or polyspikes and wave complexes, and some patients exhibited photosensitivities. The amplitudes of somatosensory and visual evoked potentials increased, and the C reflex, which is a long-loop reflex, could be recorded in all cases at rest. By the jerk-locked averaging method, a positive spike time-locked to the myoclonic jerk was demonstrated in four patients before 15-20 msec of myoclonic jerk. These findings indicated "cortical reflex myoclonus". Valproates were markedly effective for its treatment. I proposed the new term "benign adult familial myoclonic epilepsy (BAFME)" for this disease

Temperature dependence of photoluminescence spectra of undoped and electron-doped SrTiO3: Crossover from Auger recombination to single-carrier trapping

We report unusual photoluminescence (PL) behaviors in highly photoexcited SrTiO3 crystals at low temperatures. The PL spectrum and dynamics show abrupt changes below 150 K in both nondoped and electron-doped SrTiO3 samples. We clarified that the PL dynamics in both nondoped and electron-doped SrTiO3 is well described by the same simple model involving single-carrier trapping, radiative bimolecular recombination, and nonradiative Auger recombination. The unusual temperature dependence of PL dynamics is caused by the crossover from Auger recombination at high temperatures to single-carrier trapping at low temperatures. We discuss the temperature-dependent PL dynamics in conjunction with the high carrier mobility of SrTiO3 at low temperatures

Carrier Formation Dynamics in Prototypical Organic Solar Cells as Investigated by Transient Absorption Spectroscopy

Subpicosecond transient absorption spectroscopy is a powerful tool used to clarify the exciton and carrier dynamics within the organic solar cells (OSCs). In this review article, we introduce a method to determine the absolute numbers of the excitons and carriers against delay time (t) only from the photoinduced absorption (PIA) and electrochemically induced absorption (EIA) spectra. Application of this method to rr-P3HT-, PTB7-, and SMDPPEH-based OSCs revealed common aspects of the carrier formation dynamics. First, the temporal evolution of the numbers of the excitons and carriers indicates that the late decay component of exciton does not contribute to the carrier formation process. This is probably because the late component has not enough excess energy to separate into the electron and hole across the donor/acceptor (D/A) interface. Secondly, the spectroscopy revealed that the exciton-to-carrier conversion process is insensitive to temperature. This observation, together with the fast carrier formation time in OSCs, is consistent with the hot exciton picture

Usefulness of a Flexible Port for Natural Orifice Transluminal Endoscopic Surgery by the Transrectal and Transvaginal Routes

We developed a flexible port for NOTES which allows the use of conventional forceps for laparoscope-assisted surgery without change. The port is not affected by the location of the through hole in the gastrointestinal tract or vagina which elicits a problem in conventional NOTES, and its length can be adjusted during surgery by cutting the port itself. The port is made of polymer resin with a low friction coefficient. Furthermore, the port walls have a square wave structure which contributes to (1) the prevention of devices, for example, endoscope, from getting stuck at the time of insertion and retrieval, (2) the prevention of port slippage in the surgical opening for port insertion, (3) the prevention of unexpected port removal, (4) the prevention of port bore deformation, and (5) the improvement of port flexibility in the longitudinal direction. We validated the insertion and retrieval capacities of commercially available forceps for laparoscope-assisted surgery and power devices. Furthermore, we used the flexible port to conduct cholecystectomy and partial gastrectomy. We could confirm that the selection of the flexible port diameter according to the device type allowed the smooth insertion and retrieval of the device and that the port produced no air leakage. We affirmed that it is possible to conduct surgery by the cross or parallel method similarly to single port surgery. We considered that the flexible port has a potential of becoming a revolutionary port in NOTES

Interactions of a String Inspired Graviton Field

We continue to explore the possibility that the graviton in two dimensions is related to a quadratic differential that appears in the anomalous contribution of the gravitational effective action for chiral fermions. A higher dimensional analogue of this field might exist as well. We improve the defining action for this diffeomorphism tensor field and establish a principle for how it interacts with other fields and with point particles in any dimension. All interactions are related to the action of the diffeomorphism group. We discuss possible interpretations of this field.Comment: 12 pages, more readable, references adde

Perovskite Solar Cells Prepared by Advanced Three-Step Method Using Additional HC(NH2)2I Spin-Coating: Efficiency Improvement with Multiple Bandgap Structure

In the conventional two-step prepared perovskite solar cells, the CH3NH3PbI3 (MAPbI3) film usually contains an unreacted PbI2 at the interface between an electron transport layer (ETL) and a perovskite active layer. To reduce the unreacted PbI2 in the two-step prepared MAPbI3 film, we have recently reported a new three-step method, which was realized by an additional MA(I,Br) spin-coating. Here, we propose an advanced three-step method, viz., an additional HC(NH2)2I (FAI) spin-coating on the two-step prepared MAPbI3 film. The additional FAI spin-coating formed a FAxMA1–xPbI3 solid solution by the incorporation of FA ion into MAPbI3. Also, the additional FAI spin-coating yielded a FAyMA1–yPbI3 layer (y > x) by converting the unreacted PbI2, which resulted in the layered structure with different FA concentrations and hence, with the multiple bandgap structure. The best PCE of 18.1% was achieved by optimizing the FAI spin-coating process