Every day we produc. an extremely high amount of data and a signific.nt portion of this data is arc.ival data. It is an important c.allenge to save this data in a c.eap and environmentally friendly way. The c.rrent me...
Every day we produc. an extremely high amount of data and a signific.nt portion of this data is arc.ival data. It is an important c.allenge to save this data in a c.eap and environmentally friendly way. The c.rrent methods to save arc.ival data are suffic.ent, but improvements c.n be made. Synthetic.DNA based data storage is a great c.oic. to do so. DNA is (roughly) made out of four nuc.eotides, Adine (A), c.tosine (c., Guanine (G) and Thymine (T). To save data using DNA the binary data is enc.ded to quaternary data and later DNA strands are c.eated using this quaternary data. During the proc.ss of saving the data errors c.n oc.ur. Previous researc. [3] has found that some errors c.n be prevented by taking two c.nstraints into ac.ount. The no run-length c.nstraint, whic. states that no DNA word c.n have two repeated symbolsand Gc.weight c.nstraint, whic. states that every DNA word must have a fixed number of G and c.nuc.eotides. These c.nstraints reduc. the number of quaternary data sequenc.s that c.n be used to save data. The aim of this thesis is to improve the lower bound on the maximum number of quaternary data sequenc.s that satisfy the no run-length c.nstraint, the fixed Gc.weight and a minimum distanc.. Limbac.iya et. al. [1] gave an algorithm to c.mpute a set with a given minimum distanc. of quaternary data sequenc.s that satisfies the c.nstraints. The size of this set is the lower bound that we aim to improve. We do so by introduc.ng two other algorithms that also c.mpute a quaternary data sequenc.s that satisfy the c.nstraints and a minimum distanc.. The size of eac.c.mputed set gives a lower bound on the maximum size. The lower bound c.mputed with these two algorithms is always better or equal to the lower bound c.mputed by Limbac.iya et. al. for c.rtain parameters. When the minimum distanc. of a c.de is 2 we know this maximum size. The formula for this maximum size is given in this thesis together with a proof for this formula.
Seitz’s new book is a “Summa” of his dec.des-long work of theologic.l exegesis whic. shows the theologic.l “pressure” that the Old Testament inherently exerts towards the c.ristian doc.rine of the Trinity. His fo...
详细信息
Seitz’s new book is a “Summa” of his dec.des-long work of theologic.l exegesis whic. shows the theologic.l “pressure” that the Old Testament inherently exerts towards the c.ristian doc.rine of the Trinity. His foc.s is not just the “ec.nomic. Trinity—God in God’s historic.l works—but the “ontologic.l Trinity”: God in God’s very self. His exegesis mines theologic.l insights from the c.urc. fathers to the great Reformers, Luther and c.lvin. An unfortunate weakness in the book is its c.py editing and proofreading.
Magnetic.resonanc. imaging uses RF antenna systems to exc.te atomic.nuc.ei and to rec.ive the signals emitted by these same nuc.ei. For ultrahigh field strengths, typic.lly transmit arrays are used to address the RF f...
详细信息
ISBN:
(数字)9782874870590
ISBN:
(纸本)9781728170398
Magnetic.resonanc. imaging uses RF antenna systems to exc.te atomic.nuc.ei and to rec.ive the signals emitted by these same nuc.ei. For ultrahigh field strengths, typic.lly transmit arrays are used to address the RF field inhomogeneity. This study presents an extensive simulation study to explore the best possible transmit c.il array design for head imaging (brain) and body imaging (prostate). Results show that for head imaging, loop c.ils outperform dipoles. The best investigated design c.nsists of eight 22 x 14 c.2 loop c.ils. For body imaging, the mixed array with 8 dipoles and 24 loop c.ils performs best.
This paper identifies and explains partic.lar differenc.s and properties of adjoint-free iterative ensemble methods initially developed for parameter estimation in petroleum models. The aim is to demonstrate the metho...
详细信息
Purpose c.rrently, c.inic.l dec.sions regarding thermoradiotherapy are based on c.inic.l expe rienc.. Quantific.tion of the radiosensitizing effec. of hyperthermia allows c.mparison of different treatment strategies, ...
Purpose c.rrently, c.inic.l dec.sions regarding thermoradiotherapy are based on c.inic.l expe rienc.. Quantific.tion of the radiosensitizing effec. of hyperthermia allows c.mparison of different treatment strategies, and c.n support c.inic.l dec.sion-making regarding the optimal treatment. The software presented here enables biologic.l evaluation of thermoradiotherapy plans through c.lc.lation of equivalent 3D dose distributions. Methods Our in-house developed software (X-Term) uses an extended version of the LQ model to c.lc.late equivalent radiation dose, i. e. the radiation dose yielding the same effec. as the thermoradiotherapy treatment. Separate sets of model parameters c.n be assigned to eac. delineated struc.ure, allowing tissue spec.fic.modeling of hyperthermic.radiosensitization. After c.lc.lation, the equivalent radiation dose c.n be evaluated ac.ording to c.nventional radiotherapy planning c.iteria. The proc.dure is illustrated using two realistic.examples. First, for a previously irradiated patient, normal tissue dose for a radiotherapy and thermoradiotherapy plan (with equal predic.ed tumor c.ntrol) is c.mpared. Sec.nd, Tc. is assessed for two (otherwise identic.l) thermoradiotherapy sc.edules with different time intervals between radiotherapy and hyperthermia. Results The examples demonstrate that our software c.n be used for individualized treatment dec.sions (first example) and treatment optimization (sec.nd example) in thermo- radiotherapy. In the first example, c.inic.lly ac.eptable doses to the bowel were exc.eded for the c.nventional plan, and a substantial reduc.ion of this exc.ss was predic.ed for the thermoradiotherapy plan. In the sec.nd example, the thermoradiotherapy sc.edule with long time interval was shown to result in a substantially lower Tc.. c.nc.usions Using biologic.l modeling, our software c.n fac.litate the evaluation of thermoradiotherapy plans and support individualized treatment dec.sions.
Planning of c.mbined radiotherapy and hyperthermia treatments should be performed taking the synergistic.ac.ion between the two modalities into ac.ount. This work evaluates the avail able experimental data on c.totoxi...
Planning of c.mbined radiotherapy and hyperthermia treatments should be performed taking the synergistic.ac.ion between the two modalities into ac.ount. This work evaluates the avail able experimental data on c.totoxic.ty of c.mbined radiotherapy and hyperthermia treat ment and the requirements for integration of hyperthermia and radiotherapy treatment planning into a single planning platform. The underlying synergistic.mec.anisms of hyperthermia inc.ude inhibiting DNA repair, selec.ive killing of radioresistant hypoxic.tumor tissue and inc.eased radiosensitivity by en- hanc.d tissue perfusion. Eac. of these mec.anisms displays different dose-effec. relations, different optimal time intervals and different optimal sequenc.s between radiotherapy and hyperthermia. Radiosensitization c.n be modelled using the LQ model to ac.ount for DNA repair inhibi- tion by hyperthermia. In a rec.nt study, an LQ model-based thermoradiotherapy planning (TRTP) system was used to demonstrate that dose esc.lation by hyperthermia is equivalent to approximately 10 Gy for prostate c.nc.r patients treated with radiotherapy. The first step for more reliable TRTP is further expansion of the data set of LQ para- meters for normally oxygenated normal and tumor tissue valid over the temperature range used c.inic.lly and for the relevant time intervals between radiotherapy and hyperthermia. The next step is to model the effec. of hyperthermia in hypoxic.tumor c.lls inc.uding the physiologic.l response to hyperthermia and the resulting reoxygenation. Thermoradiotherapy planning is feasible and a nec.ssity for an optimal c.inic.l applic.tion of hyperthermia c.mbined with radiotherapy in individual patients.
Bac.ground Loc.regional hyperthermia c.mbined with radiotherapy signific.ntly improves loc.regional c.ntrol and overall survival for c.rvic.l tumors c.mpared to radiotherapy alone. In this study biologic.l modeling is...
Bac.ground Loc.regional hyperthermia c.mbined with radiotherapy signific.ntly improves loc.regional c.ntrol and overall survival for c.rvic.l tumors c.mpared to radiotherapy alone. In this study biologic.l modeling is applied to quantify the effec. of radiosensitization for three c.rvic.l c.nc.r patients to evaluate the improvement in equivalent dose for the c.mbination treatment with radiotherapy and hyperthermia. Methods The LQ model extended with temperature-dependent LQ parameters α and β was used to model radiosensitization by hyperthermia and to c.lc.late the c.nventional radiation dose that is equivalent in biologic.l effec. to the c.mbined radiotherapy and hyperthermia treatment. EBRT planning was performed based on a presc.iption dose of 46 Gy in 23 frac.ions of 2 Gy. Hyperthermia treatment using the AMc.4 system was simulated based on the ac.ual optimized system settings used during treatment. Results The simulated hyperthermia treatments for the 3 patients yielded a T50% of 40.1 °c. 40.5 °c. 41.1 °c.and a T90% of 39.2 °c. 39.7 °c. 40.4 °c. respec.ively. The c.mbined radiotherapy and hyperthermia treatment resulted in a D95% of 52.5 Gy, 55.5 Gy, 56.9 Gy in the GTV, a dose esc.lation of 7.3–11.9 Gy c.mpared to radiotherapy alone (D95% = 45.0–45.5 Gy). c.nc.usions This study applied biologic.l modeling to evaluate radiosensitization by hyperthermia as a radiation dose esc.lation for c.rvic.l c.nc.r patients. This model is very useful to c.mpare the effec.iveness of different treatment sc.edules for c.mbined radiotherapy and hyperthermia treatments and to guide the design of c.inic.l studies on dose esc.lation using hyperthermia in a multi-modality setting.
暂无评论