observed linear regime shown in Fig. 2a, which rein- forces the negligible charge/discharge processes of traps in this region. On the other hand, as shown in Fig. 3b, multiple peaks were observed in the Gp/ω curves while the device operated in the subthreshold region as the applied bias above the flat band voltage. In this region, the peaks steadily shift to higher frequencies with the increasing applied voltage, which is the typical Gp/ω characteristic indicating the presence of interface traps with continuous energy levels as commonly observed in conventional conductance measurements [17–19, 23]. The Gp/ω characteristics in the deep depletionregion (−1 V < V G < 0 V) are plotted in Fig. 3c which exhibits
of surface Fermi level pinning at approximately 1.15 eV below the conduction band which implies a band bend- ing potential, F ≈ 1.15 V [30,31]. Once UV light is turned on, oxygen molecules are desorbed, as photoex- cited holes become available, thereby reducing the sur- face potential F and the corresponding depletion width until a steady state is reached. Photoconductivity reflects the formation of a non-depleted core at the center of the wire, where the electron density is given by the doping level n. The changes of surface potential and the corresponding depletion width are determined by the interplay between oxygen adsorption and the net desorption rate which is a function of UV light inten- sity . However, because of the relatively high oxy- gen partial pressure in air, total elimination of the depletionregion and of the corresponding band bend- ing would require extremely high illumination inten- sity. The maximum achievable photoconductivity should correspond to the native electron density n . This explains why the saturation value of the photocurrent increases sublinearly with illumination intensity (Figure 2) [32,33].
the effect of depletionregion on transportation of charge carrier though interface. Nevertheless, after the low frequency capacitance had reached a peak, it has decreased to negative region. According to report , the de- pletion region at interface produces large number of localized defect states where the injected charge carriers gets trapped. The carriers produced induced current by escaping them from traps under high forward bias. However the time requires hoping the carrier from their traps is very slow which cause to current to lags behind the voltage applied. That led to create inductive effective or negative capacitance. In addition, the dipole effect is created also at interface from hoping motion of detrapping carrier which also contributes to negative capaci- tance.
Recall that the basic equation for the capacitance of a parallel-plate capacitor is defined by C A/d, where is the permittivity of the dielectric (insulator) between the plates of area A separated by a distance d. In the reverse-bias region there is a de- pletion region (free of carriers) that behaves essentially like an insulator between the layers of opposite charge. Since the depletion width (d) will increase with increased reverse-bias potential, the resulting transition capacitance will decrease, as shown in Fig. 1.37. The fact that the capacitance is dependent on the applied reverse-bias po- tential has application in a number of electronic systems. In fact, in Chapter 20 a diode will be introduced whose operation is wholly dependent on this phenomenon. Although the effect described above will also be present in the forward-bias re- gion, it is overshadowed by a capacitance effect directly dependent on the rate at which charge is injected into the regions just outside the depletionregion. The result is that increased levels of current will result in increased levels of diffusion capaci- tance. However, increased levels of current result in reduced levels of associated re- sistance (to be demonstrated shortly), and the resulting time constant ( RC ), which is very important in high-speed applications, does not become excessive.
Varactors are used in reverse-bias mode. The key to understanding their operation is to consider the structure of a diode, comparing it to the construction of a capacitor. Consider the depletionregion to be the dielectric of a capacitor with the anode and cathode being the capacitor plates. Consequently, all junction diodes exhibit some capacitance. Normally, designers try to minimize this effect but it is exploited with varactors. As noted in our earlier discussion, increasing the reverse-bias potential on a diode causes its depletionregion to widen. All else being equal, increasing the plate separation of a capacitor decreases its capacitance. Thus, by increasing the reverse-bias potential, we increase the effective plate spacing and decrease the diode junction capacitance. We now have a capacitance the value of which is determined by a DC bias voltage. This capacitance can be used as part of electronic tuning circuits for applications such as oscillators and filters. Compared to fixed capacitors the values tend to be small, in the tens to hundreds of picofarads, but it is sufficient for much radio frequency work. The advantages over mechanically adjustable capacitors are manifold, including small size, high reliability, low cost and the ability to rapidly change the capacitance 11 .
The BPW41N generated more current than the 2N3055 transistor because BPW41N is a PIN photodiode which has a wide depletionregion called the intrinsic region width that enhances the generation of more photocurrent and BPW41N is designed in such a way that it has a high speed of response , hence it has prompt photocurrent generation.
phenomenon can be attributed to the formation of the depletionregion when the negative voltage was added. The depletionregion decreases the electric field intensity on the dielectric layer, which resulted in a much lower leakage current density. The leakage current density of the capacitors without annealing was improved from 1 × 10 − 8 to 3 × 10 − 9 A/cm 2 at 1 V when O 3 was used as the
In this paper, we present the analysis results of survival rate estimation of population in Thailand, comparing to the survival rate to age 65 of people in China. The predictive attributes used in our study are environment factors, health expenditure, natural resource depletion, energy and mineral depletion, carbon dioxide (CO 2 ) emissions from gas, liquid,
Broadly neutralizing antibodies isolated from infected patients who are elite neutralizers have identified targets on HIV-1 enve- lope (Env) glycoprotein that are vulnerable to antibody neutralization; however, it is not known whether infection established by the majority of the circulating clade C strains in Indian patients elicit neutralizing antibody responses against any of the known targets. In the present study, we examined the specificity of a broad and potent cross-neutralizing plasma obtained from an In- dian elite neutralizer infected with HIV-1 clade C. This plasma neutralized 53/57 (93%) HIV pseudoviruses prepared with Env from distinct HIV clades of different geographical origins. Mapping studies using gp120 core protein, single-residue knockout mutants, and chimeric viruses revealed that G37080 broadly cross-neutralizing (BCN) plasma lacks specificities to the CD4 bind- ing site, gp41 membrane-proximal external region, N160 and N332 glycans, and R166 and K169 in the V1-V3 region and are known predominant targets for BCN antibodies. Depletion of G37080 plasma with soluble trimeric BG505-SOSIP.664 Env (but with neither monomeric gp120 nor clade C membrane-proximal external region peptides) resulted in significant reduction of virus neutralization, suggesting that G37080 BCN antibodies mainly target epitopes on cleaved trimeric Env. Further examina- tion of autologous circulating Envs revealed the association of mutation of residues in the V1 loop that contributed to neutral- ization resistance. In summary, we report the identification of plasma antibodies from a clade C-infected elite neutralizer that mediate neutralization breadth via epitopes on trimeric gp120 not yet reported and confer autologous neutralization escape via mutation of residues in the V1 loop.
[20, 22]. Meanwhile, germline mutations in TDG were also detected in patients with familial colorectal cancer . On the other hand, TDG expression in human cancers can also be regulated by epigenetic changes. For instance, the expression of TDG could be targeted by miR-29 family [23, 24]. In addition, TDG promoter can be hypermethylated, leading to the silencing of its expression [19, 25]. However, we found oncogenic Ras repressed TDG transcription independent of promoter hypermethylation (Supplementary Figure 1). Furthermore, we identified a novel mechanism resulting in the loss of TDG function (Figure 6). Certainly, we could not exclude other transcription factors important to activate TDG transcription. It has been reported that TDG is actually a target of p53 . However, we found no binding sites for p53 in the minimal promoter region we identified, indicating that p53 may regulate TDG transcription through other DNA elements or in a cell-specific manner.
Hesser and colleagues repeated the depletions of both METTL3 and the YTHDF proteins in both the iSLK.219 and TREX-BCBL1 cell lines and carried out a range of assays to determine the phenotypic e ﬀ ect on KSHV lytic replication . Viral transfer assays, assessing the ability of GFP-expressing virions produced in endothelial cells to reinfect 293T cells, demonstrated that depletion of DF2 and METTL3 strikingly de- creased infectious virion production. Additionally, while signi ﬁ cant reductions in the abundance of the late viral transcript ORFK8.1 were only observed for knockdown of METTL3, depletion of DF2 reduced the levels of the immediate early, delayed early and late KSHV mRNAs ORF50, ORF37 and ORFK8.1 and also the RTA and ORF59 proteins. These observations may be the result of upstream alterations in the expression of early viral transcripts which in turn cause a reduction in the levels of mRNAs expressed later during KSHV reactivation. In agreement with Tan and colleagues, no signiﬁcant or consistent eﬀect could be observed for depletion of DF1 or DF3. Surprisingly however, when Hesser and colleagues repeated these assays in TREX-BCBL1 cells, METTL3 and DF2 depletion had no signiﬁcant eﬀect on infectious virion production nor ORF50 and ORF59 mRNA levels, but increased protein levels of RTA and ORF59 indicating that m 6 A restricts KSHV
Our recent coarse-grained (CG) molecular dy- namics (MD) simulations of membranes with a hemifused-ribbon (λ-shaped) geometry showed curvature-driven demixing leading to enrich- ment in dioleoyl-phosphatidylethanolamine (DOPE) in a negatively-curved region (at C –0.8 nm –1 ) of a DOPE/dipalmitoyl-phosphati- dylcholine (DPPC) membrane. Here we extend the analysis with respect to lipid composition and simulation time. Simulations of 12 - 20 μs effective time show that, compared with DOPE of the DOPE/DPPC system, a DPPC/dilinoleyl- PC [di(18:2)PC] membrane showed a similar degree of enrichment of di(18:2)PC in the curved region with C –0.8 nm –1 . For the latter mixture, even weak negative curvatures (C –0.5 - 0.6 nm –1 ) caused significant degrees of di(18:2)PC enrichment. In agreement with recent studies of a planar bilayer, a ternary DPPC/ di(18:2)PC/cholesterol 0.42:0.28:0.3 mixture phase-separated into nanoscale raft-like liquid- ordered (L o ) and non-raft liquid-disordered (L d )
Although the findings of this study apply to only a very specialized situation such as the anchoring of localized RNAs within the vegetal cortex of oocytes, it is quite likely that other RNAs play similar roles in both germ cells and somatic cells of other organisms. In the case of Xenopus oocytes, it is clear that integration of the RNAs into the cytoskeleton is of extreme importance for the proper formation and migration of the germ cells. In other systems, the role of the RNA- Fig. 11. Effect of antisense oligonucleotide injection on primordial germ cells (PGCs) in blastula. Whole-mount in situ hybridization with digoxigenin-labeled Xpat RNA probe. Embryos were acquired by host transfer and cleared to visualize their interior. In all embryos, the side view of blastulae is shown with the animal pole at the top and the vegetal pole at the bottom. In control embryo (A), the Xpat labeled islands of germ plasm (arrows) are visible in the compact group at the vegetal tip of the blastula. In antisense VegT-injected embryos (B,C), the germ plasm is visible as the large aggregates (double arrow, B and C) and also as small aggregates dispersed within the vegetal blastomeres (arrows, B). In antisense Xlsirts injected embryos (D,E), the germ plasm was either barely visible (arrow, D) or was dispersed over the larger surface of vegetal region of the blastula (arrows, E). Scale bars: 300 μ m. The experiment was repeated three times with 20 embryos in each group.
The interaction of charged particles and photons with intense electromagnetic fields gives rise to multiphoton Compton and Breit-Wheeler processes. These are usually described in the framework of the external field approximation, where the electromagnetic field is assumed to have infinite energy. However, the multiphoton nature of these processes implies the absorption of a significant number of photons, which scales as the external field amplitude cubed. As a result, the interaction of a highly charged electron bunch with an intense laser pulse can lead to significant depletion of the laser pulse energy, thus rendering the external field approximation invalid. We provide relevant estimates for this depletion and find it to become important in the interaction between fields of amplitude a 0 ∼ 10 3 and electron bunches with charges of the
In the SNA the production boundary includes: “The production of all goods or services that are supplied to units other than their producers, or intended to be so supplied, including the production of goods or services used up in the process of producing such goods or services” (SNA 2008, 98; our italics). This production relies on social reproduction (and we argue depletion). We also know that “Economic production may be defined as an activity carried out under the control and responsibility of an institutional unit that uses inputs of labour, capital, and goods and services to produce outputs of goods or services. There must be an institutional unit that assumes responsibility…A purely natural process without any human involvement or direction is not production in an economic sense” (SNA 2008, 97-98; our italics). Now, what we have been exploring is whether the non-recognition of aspects of work (social reproduction) of an institutional unit – the household 7 - also leads to non-recognition of the ‘goods and services used up’ in this process. This non-recognition then contributes to depletion by taking social reproduction and its costs for granted and leaving these unmeasured. Thus non-valuation of both work and the resources that are used up or that ‘decrease seriously’ need to be accounted for if we are to address the issue of depletion of those engaged in social
Also, certain features seen in the allsky images are ex- plained better based on our ﬁnding that the band structures are vertically tilted MSTID structures. First, this interpreta- tion agrees with the inherit assumption of ﬁeld-alignment in the Perkins Instability theory. Second, the bands are actu- ally wider to the south relative to the north, because they reach higher altitudes to the south and the bubble shape expands probably due to vertical inhomogeneity of the F- region. If the bands are in fact vertically tilted (the tilt be- ing similar to the orientation of the magnetic ﬁeld line), that provides clues on the generation mechanism also. In the allsky images, the plasma depletion bands appear from the north, meaning they must be originated at lower altitudes, and consequently at higher latitudes as can be seen from the ﬁeld line geometry in Fig. 1(b). This suggests that these irregularities are possibly seeded by gravity waves that are generated at lower altitudes. On the contrary, plume shaped depletions appearing from the south in the allsky images during geomagnetic storms could be associated with the poleward surge of high-altitude equatorial spread-F bubbles at the magnetic equator. Studies done with the GUVI instru- ment on the TIMED satellite clearly show that the equa- torial ESF plumes might reach mid-latitudes following the magnetic ﬂux tubes (Kelley et al., 2003c; Kil et al., 2004).
In addition, the use of fitting parameters, combined with the relative simplicity of the model, suggest that the model is not meant to predict specific behavior with high accuracy. Instead, it is best utilized in characterizing existing data to allow one to gain fundamental insight into the operation of a particular device structure, and to determine how specific changes to this structure may change the device performance. As it currently stands, this model does not include a universal mobility model for the channel region, and so ballistic transport is assumed. Furthermore, this model, in its current iteration, is specific to single gate devices, and assumes some arbitrary degree of gate overlap to the source/drain regions (which cannot be varied). Therefore, the effect of ultrathin body double gate devices, as well as the effects of overlap/underlap capacitance on high frequency operation, cannot be studied with this model. Again, this is a relatively simple model, developed for the sole purpose of gaining fundamental insight.
stratosphere where ozone particles are accumulated . Ozone layer is also naturally broken down but there is a balance between its formation and natural depletion. As a result the total amount of ozone remains constant. But ozone layer thickness varies with altitude and seasonal change. Ozone concentration is highest between 19 - 23 km. Most of ozone is formed at equator where there is maximum sunshine but with winds it travels at high altitude and get accumulated in stratosphere.
´ The introduced model that assumes surface charge on the lateral sides of the depletion layer gives smaller values for the thickness of the depletion layer and the capacity of the equivalent condenser than that obtained for the model that assumes volume charge distribution in the space of the depletion layer, for the same parameters.
removal of initial acceptors. In 1000 Ω cm the acceptor removal was not directly observed and studies at lower fluences would be needed to measure this effect. It was found that acceptor removal constant is larger with protons, i.e. the removal is finished at a lower fluence than with neutrons, and that the stable damage introduction rate is lower. This results in larger depletion depths which