scholarly journals Exploring units-locating in enumerating units of 3D arrays: linking units-locating to units-representation

Author(s):  
Edgar Alstad ◽  
Maren Berre ◽  
Per Nilsson

AbstractThe aim of the present study is to explore strategies in enumerating units of three dimensional (3D) arrays. We analyse enumeration strategies of students in grade 3 (ages 8 to 9) in situations of cubical and spherical representations of units of 3D arrays. By exploring students’ strategies in these two situations, we find that difficulties in enumerating units in 3D arrays can be traced to difficulties in units-locating, with the consequence of applying double and triple counting. Our results also indicate that spherical units can serve as perceptual clues in units-locating and in assembling units into relevant composites. With input from our findings, we suggest research to investigate the following three hypotheses: (i) spherical units can turn students away from double and triple counting, (ii) spherical units can support students’ units-locating process and their ability to assemble units into relevant composites and (iii) teaching of enumerating 3D arrays should start with spherical units before cubical units.

2021 ◽  
pp. 10-14
Author(s):  
A.F. Levytskyi ◽  
◽  
V.O. Rogozinskyi ◽  
M.M. Dolianytskyi ◽  
L.V. Duda ◽  
...  

HGT is a safe technique as the world literature describes complications in the form of loosening of the pins or superficial infections of the skin around the pins, which are not significant and do not pose a threat to the patient’s life. Purpose – to improve the results of the ventilation function of the lungs in patients with complex spinal deformities through the preliminary use of halo gravity traction and to introduce an effective and safe method for the treatment of complex spinal deformities in children with respiratory dysfunctions. Materials and methods. 64 children with complex spinal deformities (>100°) were treated in the orthopedic and traumatology department of the Okhmatdet NSPU using halo gravity traction during the period from 2003 until 2018. Of these, 38 are boys and 26 are girls. The average age of the patients was 11.6 years. The average Risser score was 3.8 (P>0.01). Results. According to the data of spirography performed, 46% of patients had moderate ventilation disorders and 54% – severe ventilation disorders (FVC<60% – grade 3 and 4 of ventilation failure). Mixed type disorders were recorded in 83% of patients, and restrictive type disorders in 17% (8/48) of children. After HGT, there was an improvement in pulmonary function indicators: an increase in FVC from 63.19% to 71.77% and FEV1 from 54.71% to 65.46%, Tiffeneau-Pinelli index – from 74.59% to 85.33%. Compared with the initial level of indicators, the improvement in FVC was 13.6% after HGT and 14.6% in dynamics during the year, and FEV1 – 19.6% and 21.6%, respectively. The results obtained indicate a significant improvement in the ventilation function of the lungs, especially due to the degree of FEV1 increase, which correlates with the degree of improvement in performance, mortality and life prognosis. Conclusions. The use of HGT makes it possible to improve the results of the final correction of spinal deformity, which in turn significantly improves the ventilation function of the lungs, which in turn helps to reduce the risks of mortality due to pulmonary insufficiency in adulthood. The choice of the appropriate methods of surgical correction for complex deformity of the spine is a prerequisite for successful treatment and the achievement of three-dimensional correction of the spine to maximally approximate its parameters to the physiological norm. The indication for halo gravity traction is a rigid scoliotic deformity of the spine with a deformity angle (>100°). This study was conducted in accordance with the principles of the Helsinki Declaration. The research protocol was approved by the Local Ethics Committee of the institutions mentioned in the work. Informed parental agreement was obtained for the research. No conflict of interests was declared by the authors. Key words: spinal deformity, respiratory dysfunctions, halo-gravity traction.


Author(s):  
Andrew Cram ◽  
Russell Lowe ◽  
Katy Lumkin

There is growing interest in adopting three-dimensional virtual environments within spatial design courses to use digital modelling techniques to support students' learning. One pedagogical issue that has received little attention so far is the question of how 3D virtual environments can be used to implement assessment techniques that support students' learning of spatial design expertise. This chapter seeks to assist spatial design educators who are considering digital modelling by presenting two case studies that highlight assessment practices within spatial design courses using virtual environments. Rubrics and student work samples are included. These courses both involve students creating architectural designs within virtual environments, yet contrast in several ways: learning outcomes, 3D modelling technologies, and student cohorts. The cases examine how the affordances of virtual environments for iterative, immersive, and collaborative design can enable formative and summative assessment, with both design process and the final artefact playing important roles.


2000 ◽  
Vol 18 (9) ◽  
pp. 1936-1941 ◽  
Author(s):  
Michael J. Zelefsky ◽  
William K. Kelly ◽  
Howard I. Scher ◽  
Henry Lee ◽  
Tracy Smart ◽  
...  

PURPOSE: To assess the feasibility and tolerance of neoadjuvant and concomitant estramustine phosphate and vinblastine (EV) with high-dose three-dimensional conformal radiotherapy (3D-CRT) for patients with unfavorable-risk prostate cancer. PATIENTS AND METHODS: Twenty-seven patients with unfavorable-risk prostate cancer were enrolled onto a prospective study to determine the feasibility of combining EV with 3D-CRT. Patients were eligible if any of the following requirements were satisfied: (1) Gleason score ≥ 8 and prostate-specific antigen (PSA) > 10 ng/mL; (2) Gleason score of 7 and PSA > 20 ng/mL; (3) clinical stage T3N0M0 disease with PSA > 20 ng/mL; (4) any patient with T4N0M0 disease; or (5) patients with TXN1MO disease. Therapy consisted of three 8-week cycles of EV and 8 weeks of 3D-CRT. Estramustine phosphate was given orally beginning on week 1 and continued until the completion of 3D-CRT. Each 8-week cycle of vinblastine consisted of 6 weekly intravenous injections followed by a 2-week rest period. Radiation therapy was administered using a three-dimensional conformal approach to a prescription dose of 75.6 Gy. The median follow-up was 26 months (range, 6 to 40 months). RESULTS: Twenty-three (85%) of 27 patients completed the entire course of therapy and were assessable for toxicities and biochemical outcome. Two patients (7%) developed grade 3 hematologic toxicity that resolved, and two patients (7%) developed grade 3 hepatoxicity, manifesting as persistent elevation of serum transaminase levels, necessitating discontinuation of the chemotherapy and withdrawal from the treatment program. The most prominent adverse effects from this regimen were mild to moderate (grade 1 to 2) nausea and fatigue related to estramustine. Mild peripheral edema was seen in 15% of patients and was treated with diuresis. 3D-CRT was tolerated well in these patients. Medications were required for relief of acute grade 2 rectal (gastrointestinal [GI]) and urinary (genitourinary [GU]) symptoms in 35% and 48% of patients, respectively. Three patients developed acute grade 3 GU toxicities. The 2-year actuarial likelihood of late grade 2 GI toxicity was 20%. No late grade 3 or 4 GI toxicities were observed. The 2-year actuarial likelihoods of late grade 2 and 3 GU toxicities were 25% and 12%, respectively. No grade 4 GU toxicity was observed. CONCLUSION: Neoadjuvant and concomitant EV with high-dose 3D-CRT is well tolerated in patients with unfavorable-risk prostate cancer. Although the incidence of modest (grade 2) late GI and GU toxicities seem to be increased compared with 3D-CRT alone or in combination with androgen ablation therapy, no severe toxicities were encountered with this regimen.


Author(s):  
Yukun Zhang ◽  
Shaohua Tu ◽  
Lian Duan ◽  
Weilun Fu ◽  
Jianbo Wang ◽  
...  

Abstract Introduction To help diagnose and evaluate the prognosis of pituitary adenoma with cavernous sinus (CS) invasion and guide endonasal endoscopic surgery (EES) assisted by intraoperative navigation (ION) with three-dimensional multimodal imaging (3D-MMI). We propose a classification of CS invasion based on 3D-MMI. Methods We picked some appropriate cases and reconstructed the 3D-MMI and then classified them into 3 grades according to the stereo relationship among ICA, tumor and CS in 3D-MMI. Then, we applied different strategies according to their grade to remove pituitary adenomas that invaded the CS. Results All 38 patients were divided into 3 grades. Tumors compressing the ICA and CS without CS invasion were divided into grade 1. Tumors encasing the ICA and invading the superior-posterior compartment and/or anterior-inferior compartment but without distinct separation of the ICA and CS lateral wall were deemed as grade 2. Tumors encasing the ICA and filling the lateral compartment of the CS that dissociated the lateral wall from the ICA were deemed as grade 3. The 3D-MMI enabled adequate spatial visualization of the ICA, CS and tumors. All patients were operated on under the guidance of ION with 3D-MMI. Conclusions Classification based on 3D-MMI can better demonstrate the relationships among tumor, ICA and CS in a stereo and multi-angle view, which will have significance in guiding the surgical strategy.


2008 ◽  
Vol 26 (6) ◽  
pp. 942-947 ◽  
Author(s):  
William Small ◽  
Jordan Berlin ◽  
Gary M. Freedman ◽  
Theodore Lawrence ◽  
Mark S. Talamonti ◽  
...  

Purpose Gemcitabine is effective in the treatment of pancreatic cancer and is a potent radiosensitizer. This study assessed safety and efficacy of full-dose gemcitabine administered before and during concurrent three-dimensional conformal radiation (3D-CRT) in patients with nonmetastatic pancreatic cancer. Patients and Methods During cycles 1 and 3, patients received gemcitabine at 1,000 mg/m2 on days 1 and 8 of each 21-day cycle. Cycle 2 included the same dose of gemcitabine on days 1, 8, and 15 of a 28-day cycle with concurrent 3D-CRT at 36 Gy, administered in 15 fractions of 2.4 Gy, over 3 weeks. Resectable patients underwent surgery 4 to 6 weeks after treatment. The primary objective was evaluation of toxicity. Tumor response, CA 19-9, and 1-year survival were also assessed. Results Forty-one patients enrolled at six institutions between April 2002 and October 2003. Among the 39 treated patients, the most common toxicities were grade 3 neutropenia (12.8%), grade 3 nausea (10.3%), and grade 3 vomiting (10.3%). The response rate was 5.1% and disease control rate was 84.6%. Mean post-treatment CA 19-9 levels (228 ± 347 U/mL) were significantly (P = .006) reduced compared with pretreatment levels (1,241 ± 2,124 U/mL). Thirteen (81%) of 16 patients initially judged resectable, three (33%) of nine borderline-resectable patients, and one (7%) of 14 unresectable patients underwent resection after therapy. One-year survival rates were 73% for all patients, 94% for resectable patients, 76% for borderline-resectable patients, and 47% for unresectable patients. Conclusion Full-dose gemcitabine with concurrent radiotherapy was well tolerated and active. Evaluation of this regimen in a larger, randomized trial for patients with resectable or borderline-resectable disease may be warranted.


2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 3082-3082 ◽  
Author(s):  
R. F. Marschke ◽  
A. D. Ricart ◽  
D. D. Von Hoff ◽  
J. K. Lim ◽  
K. Papadopoulos

3082 Background: CX-3543 is a novel small molecule specifically designed to target three dimensional nucleic acid motifs, and thus induce apoptosis in cancer cells. Preclinically, CX-3543 demonstrated potency in suppressing xenograft tumor growth with a broad therapeutic window. The objectives of this phase I study are: to determine the maximum tolerated dose (MTD) and dose limiting toxicities (DLTs), to establish the pharmacokinetics (PKs), and to determine the recommended dose for further clinical development of CX-3543. Methods: Eligible patients with advanced solid tumors or lymphomas whose tumors progressed on standard therapy or for whom there are no standard therapies receive CX-3543 in successive dose cohorts at: 10, 20, 40, 80 and 160 mg/m2. Dosing is by one hour intravenous infusion daily for five consecutive days repeated on a three week cycle. Therapy is continued until the patient shows signs of intolerance to CX-3543 or evidence of advancing disease. Response by RECIST criteria is determined after every 2 cycles. Results: Ten patients with solid tumors (3–4 per cohort) have received intravenous CX-3543. Doses have been well tolerated. Seven grade 3 adverse events have been reported during the study, but none of these are related to CX-3543. To date no objective responses have been observed. One patient with advanced refractory prostate cancer has stable disease of longer than 4 months duration. CX-3543 has demonstrated good linearity in PK parameters between the dose cohorts with a terminal half life of approximately 12 hours following the first dose. Conclusions: To date, CX-3543 has shown no drug related toxicity and has predictable PKs. No DLTs have yet been observed, and the MTD remains to be defined in this Phase I study. Further enrollment to the planned dose escalation cohorts is ongoing. [Table: see text]


2007 ◽  
Vol 17 (1) ◽  
pp. 55-60 ◽  
Author(s):  
A. A. Garsa ◽  
R. S. Andrade ◽  
D. E. Heron ◽  
S. Beriwal ◽  
H. Kim ◽  
...  

This study assesses the feasibility and implementation of respiratory-gated whole-abdominal intensity-modulated radiation therapy (RG-WAIMRT). Three patients were treated with RG-WAIMRT. The planning target volume (PTV1) included the entire peritoneal cavity and a pelvic boost field was created (PTV2). The dose prescribed was 30 Gy to PTV1 and 14.4 Gy to PTV2. For comparison, a conventional three-dimensional (3D) plan was generated for each patient. In the WAIMRT plan, an average of 90% of PTV1 received 30 Gy compared to 70% for the conventional 3D plan. The percent volume receiving 30 Gy (V30) for liver averaged 54% (WAIMRT) vs 43% (3D). The percent volume receiving 20 Gy (V20) for kidneys averaged 19% vs 0%, and the mean V20 for bone marrow was 74% vs 83%, respectively. Major acute toxicities were anemia (grade 2: 1/3), leukopenia (grade 3: 2/3 patients), and thrombocytopenia (grade 2: 1/3 patients, grade 3: 1/3 patients). One patient could not complete the whole-abdomen field after 19.5 Gy because of persistent nausea. No major subacute toxicity has been reported. WAIMRT demonstrated superior target coverage and reduced dose to bone marrow, with a slightly increased dose to liver and kidneys. WAIMRT is a novel and feasible technique for ovarian cancer treatment.


2010 ◽  
Vol 13 (5) ◽  
pp. 606-611 ◽  
Author(s):  
Yoshimoto Ishikawa ◽  
Tokumi Kanemura ◽  
Go Yoshida ◽  
Zenya Ito ◽  
Akio Muramoto ◽  
...  

Object The authors performed a retrospective clinical study to evaluate the feasibility and accuracy of cervical pedicle screw (CPS) placement using 3D fluoroscopy-based navigation (3D FN). Methods The study involved 62 consecutive patients undergoing posterior stabilization of the cervical spine between 2003 and 2008. Thirty patients (126 screws) were treated using conventional techniques (CVTs) with a lateral fluoroscopic view, whereas 32 patients (150 screws) were treated using 3D FN. Screw positions were classified into 4 grades based on the pedicle wall perforations observed on postoperative CT. Results The prevalence of perforations in the CVT group was 27% (34 screws): 92 (73.0%), 12 (9.5%), 6 (4.8%), and 16 (12.7%) for Grade 0 (no perforation), Grade 1 (perforation < 1 mm), Grade 2 (perforation ≥ 1 and < 2 mm), and Grade 3 (perforation ≥ 2 mm), respectively. In the 3D FN group, the prevalence of perforations was 18.7% (28 screws): 122 (81.3%), 17 (11.3%), 6 (4%), and 5 (3.3%) for Grades 0, 1, 2, and 3, respectively. Statistical analysis showed no significant difference in the prevalence of Grade 1 or higher perforations between the CVT and 3D FN groups. A higher prevalence of malpositioned CPSs was seen in Grade 2 or higher (17.5% vs 7.3%, p < 0.05) in the 3D FN group and Grade 3 (12.7% vs 7.3%, p < 0.05) perforations in the CVT group. The ORs for CPS malpositioning in the CVT group were 2.72 (95% CI 1.16–6.39) in Grade 2 or higher perforations and 3.89 (95% CI 1.26–12.02) in Grade 3 perforations. Conclusions Three-dimensional fluoroscopy-based navigation can improve the accuracy of CPS insertion; however, severe CPS malpositioning that causes injury to the vertebral artery or neurological complications can occur even with 3D FN. Advanced techniques for the insertion of CPSs and the use of modified insertion devices can reduce the risk of a malpositioned CPS and provide increased safety.


2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
B Yagmur ◽  
E Simsek ◽  
M Ozbaran ◽  
C Soydas Cinar

Abstract Background Early diagnosis of atrial myxomas may be a challenge because of their synptoms are often nonspecific. Two-dimensional echocardiography is the diagnostic procedure of choice. Case presentation A 42-year-old woman presented with complaints of palpitation and fatigue. Physical examination revealed a diastolic murmur at the apex. Two-dimensional transthoracic echocardiography revealed an extremely mobile mass in the left atrium that consisted of multiple cystic and solid parts. Three-dimensional transesophageal echocardiography showed that the 4.3x3.3 cm mass was connected to the interatrial septum through a 0.7 cm pedincle, and it moved between the atrium and the ventricle through the mitral valve with each carciac cycle. Grade 1 mitral and aortic regurgitation and grade 3 tricuspid regurgitation was accompanied by a SPAP of 90 mmHG. The mass was surgically excised. Histopathologic diagnosis was myxoma. Discussion Types of cystic masses that can appear in the left atrium are myxomas, hydatid cysts and interatrial septal aneurysms. In our case report, echocardiographic findings of a mass that was connected to the IAS with a pedicle were supportive of cardiac myxoma. If not removed, myxomas may cause major complications like stroke, rupture, and hemodynamic problems. Surgery was indicated because the mass was cystic and highly mobile. Abstract P174 Figure. mass


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