Excellent color rendering indexes of multi-package white LEDs

This study introduces multi-package white light-emitting diodes (LEDs) system with the ability to realize high luminous efficacy and an excellent color rendering index (CRI, R a) using the R B,M A B,M G B,M C B (R B,M A B,M G B,M denoted as a long-pass dichroic filter (LPDF)-capped, monochromatic red, amber and green phosphor converted-LED (pc-LED) pumped by a blue LED chip, and C B denoted as a cyan and blue mixed pc-LED pumped by a blue LED) system. The luminous efficacy and color rendering index (CRI) of multi-package white LED systems are compared while changing the concentration of the cyan phosphor used in the paste of a cyan-blue LED package and the driving current of individual LEDs in multi-package white LEDs at correlated color temperatures (CCTs) ranging from 6,500 K (cold white) to 2,700 K (warm white) using a set of eight CCTs as specified by the American National Standards Institute (ANSI) standard number C78.377-2008. A R B,M A B,M G B,M C B white LED system provides high luminous efficacy (≥ 96 lm/W) and a color rendering index (≥ 91) encompassing the complete CCT range. We also compare the optical properties of the R B,M A B,M G B,M C B system with those of the R B,M A B,M G B,M B and RAGB (red, amber, green, and blue semiconductor-type narrow-spectrum-band LEDs) systems. It can be expected that the cyan color added to a blue LED in multi-package white LEDs based on LPDF-capped, phosphor-converted monochromatic LEDs will meet the needs of the high-quality, highly efficient, full-color white LED lighting market in the near future.

Functional regeneration of a severed peripheral nerve with a 7-mm gap in rats through the use of an implantable electrical stimulator and a conduit electrode with collagen coating

OBJECTIVE

This paper examined the efficacy of an implantable electrical stimulator in rats for the functional regeneration of peripheral nerves.

MATERIALS AND METHODS

The implantable electrical stimulator was fabricated on a polyimide-based conduit with an integrated electrode, a stimulation chip, and a battery; 3 mg/mL of collagen gel was coated onto the conduit surface and electrical stimulation (20 µ A, 100 µ s, and 100 Hz biphasic current) was continuously applied between the nerve stumps for four weeks. The stimulator was tested on a severed sciatic nerve with a 7-mm gap in rats. The effects of both the electrical stimulation and the collagen application were examined.

RESULTS

Functionality was evaluated through walk track assessments and by recording the action potential of the regenerated nerve. Immunohistochemical staining of the regenerated nerve was done using peripheral myelin protein 22.

CONCLUSION

The results suggest that the functional recovery of a severed peripheral nerve by the proposed implantable electrical stimulator was achieved through electrical current stimulation along the use of a collagen coating on the conduit surface.

Predictors for lymph node metastasis in T1 colorectal cancer

BACKGROUND AND STUDY AIMS

It is critical that the risk of lymph node metastasis (LNM) is evaluated for determining the suitability of endoscopic resection for T1 colorectal cancer (CRC). Reported risk factors for LNM in completely resected T1 CRC are deep submucosal invasion, grade 3, angiolymphatic invasion, and budding. The aim of the present study was to identify the histopathologic factors associated with LNM in T1 CRC.

PATIENTS AND METHODS

The study involved 435 patients with T1 CRC treated by endoscopic or surgical resection between January 2001 and April 2010 at the National Cancer Center, Korea. The 435 patients were classified into two groups - those undergoing surgical resection (n = 324) and those undergoing endoscopic resection (n = 111). In the surgically resected group, details regarding depth of submucosal invasion, angiolymphatic invasion, tumor grade, budding, and background adenoma (BGA) were evaluated with respect to presence or absence of LNM. In the endoscopically resected group, the results of follow-ups and additional salvage surgeries were studied.

RESULTS

In the surgically resected group, LNM was detected in 42 patients (13.0 %). Grade 3, angiolymphatic invasion, budding, and the absence of BGA were identified as factors associated with LNM in univariate and multivariate analyses (P < 0.05). Among the 50 patients in the endoscopically resected group with high risk, three were diagnosed as being LNM-positive during the follow-up period. There was no LNM in the endoscopically resected group with low risk.

CONCLUSIONS

Grade 3, angiolymphatic invasion, budding, and the absence of BGA are the risk factors that predict LNM in patients with T1 CRC. In cases where endoscopically resected T1 CRC has no risk factor, cautious follow-up could be recommended. However, if the tumor has any risk factor, additional surgical resection should be considered.

Toward scatter-free phosphors in white phosphor-converted light-emitting diodes

Scatter-free phosphors promise to suppress the scattering loss of conventional micro-size powder phosphors in white phosphor-converted light-emitting diodes (pc-LEDs). Large micro-size cube phosphors (~100 μm) are newly designed and prepared as scatter-free phosphors, combining the two scatter-free conditions of particles based on Mie's scattering theory; the grain size or grain boundary was smaller than 50 nm and the particle size was larger than 30 μm. A careful evaluation of the conversion efficiency and packaging efficiency of the large micro-size cube phosphor-based white pc-LED demonstrated that large micro-size cube phosphors are an outstanding potential candidate for scatter-free phosphors in white pc-LEDs. The luminous efficacy and packaging efficiency of the Y(3)Al(5)O(12):Ce(3+) large micro-size cube phosphor-based pc-LEDs were 123.0 lm/W and 0.87 at 4300 K under 300 mA, which are 17% and 34% higher than those of commercial powder phosphor-based white LEDs (104.8 lm/W and 0.65), respectively. In addition, the introduction of large micro-size cube phosphors can reduce the wide variation in optical properties as a function of both the ambient temperature and applied current compared with those of conventional powder phosphor-based white LEDs.

Lymph node ratio is an independent prognostic factor in patients with rectal cancer treated with preoperative chemoradiotherapy and curative resection

PURPOSE

To evaluate the prognostic effect of lymph node ratio (LNR) in patients with locally advanced rectal cancer who were treated with curative resection after preoperative chemoradiotherapy (CRT).

METHODS

Between October 2001 and December 2007, 519 patients who had undergone curative resection of primary rectal cancer after preoperative CRT were enrolled. Of these, 154 patients were positive for lymph node (LN) metastasis and were divided into three groups according to the LNR (≤ 0.15 [n=80], 0.16-0.3 [n=44], >0.3 [n=30]) to evaluate the prognostic effect on overall survival (OS) and disease-free survival (DFS).

RESULTS

LNR (≤ 0.15, 0.16-0.3, and >0.3) was significantly associated with 5-year OS (90.3%, 75.1%, and 45.1%; p<0.001) and DFS (66.7%, 55.8%, and 21.9%; p<0.001) rates. In a multivariate analysis, LNR (≤ 0.15, 0.16-0.3, and >0.3) was a significant independent prognostic factor for OS (hazard ratios [HRs], 1, 3.609, and 8.197; p<0.001) and DFS (HRs, 1, 1.699, and 3.960; p<0.001). LNR had a prognostic impact on OS and DFS in patients with <12 harvested LNs, as well as in those with ≥ 12 harvested LNs (p<0.05).

CONCLUSION

LNR was a significant independent prognostic predictor for OS and DFS in patients with locally advanced rectal cancer who were treated with curative resection after preoperative CRT.

Highly-efficient, tunable green, phosphor-converted LEDs using a long-pass dichroic filter and a series of orthosilicate phosphors for tri-color white LEDs

This study introduces a long-pass dichroic filter (LPDF) on top of a phosphor-converted LED (pc-LED) packing associated with each corresponding tunable orthosilicate ((Ba,Sr)2SiO4:Eu) phosphor in order to fabricate tunable green pc-LEDs. These LPDF-capped green pc-LEDs provide luminous efficacies between 143–173 lm/W at 60 mA in a wavelength range between 515 and 560 nm. These tunable green pc-LEDs can replace green semiconductor-type III-V LEDs, which present challenges with respect to generating high luminous efficacy. We also introduce the highly-efficient tunable green pc-LEDs into tri-color white LED systems that combine an InGaN blue LED and green/red full down-converted pc-LEDs. The effect of peak wavelength in the tunable green pc-LEDs on the optical properties of a tri-color package white LED is analyzed to determine the proper wavelength of green color for tri-color white LEDs. The tri-color white LED provides excellent luminous efficacy (81.5–109 lm/W) and a good color rendering index (64–87) at 6500 K of correlated color temperature (CCT) with the peak wavelength of green pc-LEDs. The luminous efficacy of the LPDF-capped green monochromatic pc-LED and tri-color package with tunable green pc-LEDs can be increased by improving the external quantum efficiency of blue LEDs and the conversion efficiency of green pc-LEDs.

Catastrophic massive intracardiac thrombus in a 40-year-old patient with dilated cardiomyopathy

Dilated cardiomyopathy has been associated with left ventricular (LV) thrombosis which leads to substantial morbidity and mortality as a site for systemic emboli. We report an interesting case of a stroke and acute limb ischemia secondary to a large mobile pedunculated LV thrombus in 40-year-old patient with dilated cardiomyopathy.

Highly efficient full-color display based on blue LED backlight and electrochromic light-valve coupled with front-emitting phosphors

We report a novel full-color display based on the generation of full-color by blue light approach, so called color-by-blue display. This newly proposed color-by-blue light-valve display combines a blue backlight excitation source, a blue light-valve shutter, and front-emitting phosphor pixels. Careful evaluation shows that the detailed display characteristics as well as excellent cycling durability under a low operation voltage of 3 V easily satisfy the requirements for the current display application. Also, we would like to emphasize that the proposed method shows a conversion efficiency of 20%, surpassing the value (≈5%) seen in the typical liquid crystal displays. Although the switching response reported here is slower than in a commercial display module due to the solution-phase electrochromic nature of the shutter used, a response time close to that of a liquid crystal display is highly feasible, as we suggest.

Towards expansion of human hair follicle stem cells in vitro

OBJECTIVES

Multipotential human hair follicle stem cells can differentiate into various cell lineages and thus are investigated here as potential autologous sources for regenerative medicine. Towards this end, we have attempted to expand these cells, directly isolated from minimal amounts of hair follicle explants, to numbers more suitable for stem-cell therapy.

MATERIALS AND METHODS

Two types of human follicle stem cells, commercially available and directly isolated, were cultured using an in-house developed medium. The latter was obtained from bulge areas of hair follicles by mechanical and enzymatic dissociation, and was magnetically enriched for its CD200(+) fraction. Isolated cells were cultured for up to 4 weeks, on different supports: blank polystyrene, laminin- and Matrigel(TM) -coated surfaces.

RESULTS

Two-fold expansion was found, highlighting the slow-cycling nature of these cells. Flow cytometry characterization revealed: magnetic enrichment increased the proportion of CD200(+) cells from initially 43.3% (CD200+, CD34: 25.8%; CD200+, CD34+: 17.5%) to 78.2% (CD200+, CD34: 41.5%; CD200+, CD34+: 36.7%). Enriched cells seemed to have retained and passed on their morphological and molecular phenotypes to their progeny, as isolated CD200(+) presenting cells expanded in our medium to a population with 80% of cells being CD200(+): 51.5% (CD200(+), CD34(-)) and 29.6% (CD200(+), CD34(+)).

CONCLUSIONS

This study demonstrates the possibility of culturing human hair follicle stem cells without causing any significant changes to phenotypes of the cells.

Comparative study of NOTES rectosigmoidectomy in a swine model: E-NOTES vs. P-NOTES

BACKGROUND AND STUDY AIMS

Several reports have demonstrated the safety of pure natural-orifice transluminal endoscopic surgery (P-NOTES) using transanal endoscopic microsurgery (TEM) and embryonic NOTES (E-NOTES; laparoscopic surgery through the umbilicus). This study was performed to compare the safety and applicability of NOTES rectosigmoidectomy between E-NOTES and P-NOTES in a swine model.

PATIENTS AND METHODS

E-NOTES was conducted through a single port using laparoscopic instruments (n = 11). P-NOTES was performed using TEM with transgastric endoscopic assistance (n = 11). Gastrotomies were created using a needle knife and the balloon dilatation technique, and closed using T-anchors. Blood samples were collected to evaluate changes in systemic cytokine levels during the preoperative and postoperative periods; operative outcomes were also evaluated and compared between the groups. The necropsy findings were recorded after sacrifice at 1 week after the procedure.

RESULTS

The mean operative time for P-NOTES was significantly longer than that for E-NOTES (239 vs. 103 minutes, P < 0.001). The mean distance from the anal verge to colorectal anastomosis in the P-NOTES group was significantly less than that in the E-NOTES group (2.9 vs. 17.6 cm, P < 0.001). On necropsy, the complication rate of P-NOTES was higher than that of E-NOTES, but without statistical significance (54.5 % vs. 18.2 %, P = 0.091). The differences in changes in TNF-α, C-reactive protein, interleukin-6, and interleukin-1β between P-NOTES and E-NOTES were not significant.

CONCLUSIONS

E-NOTES rectosigmoidectomy in the swine model is safe, but remains challenging for use in pelvic dissection. P-NOTES rectosigmoidectomy using TEM may be a promising tool for pelvic dissection, but the transgastric approach involves a high degree of risk.

New paradigm of multi-chip white LEDs: combination of an InGaN blue LED and full down-converted phosphor-converted LEDs

This study introduces innovative multi-chip white LED systems that combine an InGaN blue LED and green/red or green/amber/red full down-converted, phosphor-conversion LEDs (pc-LEDs). Efficient green, amber, and red full down-converted pc-LEDs were fabricated by simply capping a long-wave pass filter (LWPF) on top of LED packing associated with each corresponding powder phosphor. The principal advantage of this type of color-mixing approach in newly developed multi-chip white LEDs based on colored pc-LEDs is thought to be dynamic control of the chromaticity and better light quality. In addition, the color-mixing approach improves the low efficacy of green/amber LEDs in the "green gap" wavelength; reduces the wide color/efficacy variations of each primary LED with at different temperatures and currents; and improves the low color rendering indexes of the traditional color-mixing approach in red, green, and blue (RGB) multi-chip white LEDs.

The realization of a whole palette of colors in a green gap by monochromatic phosphor-converted light-emitting diodes

A variety of efficient green, yellow, and amber monochromatic phosphor-converted light-emitting diodes (pc-LEDs) were fabricated by simply capping a long-wave pass filter (LWPF) on top of LED packing associated with each corresponding powder phosphor. In this paper, the luminous efficacy and color purity of two green, three yellow, and two amber pc-LEDs were reviewed by comparing the optical properties and current/temperature stability of each LWPF-capped pc-LED. The simple combination of LWPFs and phosphor materials in the pc-LEDs provide a simple means of addressing the low luminous efficacy problem of III-V monochromatic semiconductor LEDs in the various colors of the wavelength range between green and amber (known as the "green gap"). This technique also represents a simple approach to mitigate the sub-linearity problem of the efficacy versus the driving current occurring at a relatively low current in III-V green LEDs (known as "green droop") to the level of a blue LED. This nano-multilayered filter-capped pc-LED can open further research into developing new color-converting materials (such as powder phosphors, and/or quantum dots) to extend the color palette in the wavelength region of the "green gap" and to improve the efficacy and color purity of color pc-LEDs.

Clinicopathological differences of laterally spreading tumors of the colorectum according to gross appearance

BACKGROUND AND STUDY AIMS

Laterally spreading tumors (LST) are classified into two subtypes, with the nongranular type harboring a higher risk of (pre)malignant changes than the granular type. Further subdifferentiation into two subgroups each has been suggested, but the clinical significance of such a subdifferentiation has not previously been studied in detail in larger numbers.

PATIENTS AND METHODS

Out of 6499 patients diagnosed with colorectal adenomas between January 2006 and November 2008, 153 patients (2.35 %) had 158 LSTs, 96 with a granular and 62 with a nongranular pattern. The former group was subdivided into homogeneous and nodular mixed, the latter group into flat elevated and pseudodepressed. Clinical and histopathological parameters were compared among the four subtypes.

RESULTS

Parameters were variably distributed between the four groups, with nodular mixed tumors being larger than the other three types ( P < 0.0001). As in other studies, malignant transformation and premalignant lesion (HGIN/CIS) were more frequent in nodular mixed than in homogeneous tumors (45.0 % vs. 5.6 %, P < 0.001), and also more common in pseudodepressed than in flat elevated tumors (41.7 % vs. 13.2 %, P = 0.011). Submucosal invasive cancer was present in 8.3 % of nodular mixed tumors, 7.9 % of flat elevated, and 12.5 % of pseudodepressed, while it was absent in homogeneous tumors. Serrated adenoma was identified in 10.8 % of all LSTs, and sessile serrated adenoma tended to be more common in flat elevated tumors.

CONCLUSIONS

Further subdifferentiation of the LST lesions to identify lesions at risk of malignant transformation makes most sense in the granular type. Among nongranular LSTs, both subtypes carry a significant risk.

Promising efficacy of Escherichia coli recombinant human bone morphogenetic protein-2 in collagen sponge for ectopic and orthotopic bone formation and comparison with mammalian cell recombinant human bone morphogenetic protein-2

Nonglycosylated recombinant human bone morphogenetic protein (rhBMP)-2 prepared in Escherichia coli (E. coli rhBMP-2) has recently been considered as an alternative to mammalian cell rhBMP-2. However, its clinical use is still limited owing to lack of evidence for osteogenic activity comparable with that of mammalian cell rhBMP-2 via microcomputed tomography-based analysis. Therefore, this study aimed to evaluate the ability of E. coli rhBMP-2 in absorbable collagen sponge to form ectopic and orthotopic bone and to compare it to that of mammalian rhBMP-2. In vitro investigation was performed to study osteoblast differentiation of human mesenchymal stromal cells. Both types of rhBMP-2 enhanced proliferation, alkaline phosphatase activity, and matrix mineralization of human mesenchymal stromal cells at similar levels. Similar tendencies were observed in microcomputed tomography analysis, which determined bone volume, fractional bone volume, trabecular thickness, trabecular separation, bone mineral density, and other characteristics. Histology from an in vivo osteoinductivity test and from a rat calvarial defect model demonstrated a dose-dependent increase in local bone formation. The E. coli rhBMP-2 group (5 μg) not only induced complete regeneration of an 8-mm critical-sized defect at 4 weeks, but also led to new bone with the same bone mineral density as normal bone at 8 weeks, with the same efficiency as that of mammalian cell rhBMP-2 (5 μg). These uniformly favorable results provide evidence that the osteogenic activity of E. coli rhBMP-2 is not inferior to that of mammalian cell rhBMP-2 despite its low solubility and lack of gylcosylation. These results suggest that the application of E. coli rhBMP-2 in absorbable collagen sponge may be a promising equivalent to mammalian cell rhBMP-2 in bone tissue engineering.

Full down-conversion of amber-emitting phosphor-converted light-emitting diodes with powder phosphors and a long-wave pass filter

This paper reports the possibility of a facile optical structure to realize a highly efficient monochromatic amber-emitting light-emitting diode (LED) using a powder-based phosphor-converted LED combined with a long-wave pass filter (LWPF). The capping of a blue-reflecting and amber-passing LWPF enhances both the amber emission from the silicate amber phosphor layer and the color purity due to the blocking and recycling of the pumping blue light from the InGaN LED. The enhancement of the luminous efficacy of the amber pc-LED with a LWPF (phosphor concentration 20 wt%, 39.4 lm/W) is 34% over that of an amber pc-LED without a LWPF (phosphor concentration 55 wt%, 29.4 lm/W) at 100 mA and a high color purity (>96%) with Commission International d'Eclairage (CIE) color coordinates of x=0.57 and y=0.42.

The level of vitamin D in the serum correlates with fatty degeneration of the muscles of the rotator cuff

This study examined the role of vitamin D as a factor accounting for fatty degeneration and muscle function in the rotator cuff. There were 366 patients with disorders of the shoulder. A total of 228 patients had a full-thickness tear (group 1) and 138 patients had no tear (group 2). All underwent magnetic resonance arthrography and an isokinetic muscle performance test. The serum concentrations of vitamin D (25(OH)D(3)) were measured. In general, a lower serum level of vitamin D was related to higher fatty degeneration in the muscles of the cuff. Spearman's correlation coefficients were 0.173 (p = 0.001), -0.181 (p = 0.001), and -0.117 (p = 0.026) for supraspinatus, infraspinatus and subscapularis, respectively. In group 1, multivariate linear regression analysis revealed that the serum level of vitamin D was an independent variable for fatty degeneration of the supraspinatus and infraspinatus. The serum vitamin D level has a significant negative correlation with the fatty degeneration of the cuff muscle and a positive correlation with isokinetic muscle torque.

Effects of bed height on the performance of chest compressions

OBJECTIVES

The correct chest compression technique was emphasised to enhance the result of cardiopulmonary resuscitation in the 2005 guidelines. The present study compared the effects of different bed heights, including a bed at knee height, on the performance of chest compressions.

METHODS

Twenty-four healthcare providers participated in this study. Knee height was defined as the baseline bed height. Bed heights were adjusted to 10 and 20 cm above the baseline and 10 and 20 cm below the baseline. At the five bed heights, chest compressions were performed for 2 minutes, and the compression rate was maintained at 100 per minute, with audible feedback.

RESULTS

The mean compression depths (MCD) were 28.3 mm (SD 10.7; knee height +20 cm), 32.3 mm (SD 9.2; knee height +10 cm), 32.7 mm (SD 8.5; knee height), 32.3 mm (SD 9.0; knee height -10 cm) and 31.1 mm (SD 8.5; knee height -20 cm). The MCD was significantly lower at knee height plus 20 cm (p<0.001).

CONCLUSION

The performance of chest compressions decreased when the bed height was 20 cm higher than the knee height of the rescuer.

Survival of patients with skeletal metastases from hepatocellular carcinoma after surgical management

Skeletal metastases from hepatocellular carcinoma are highly destructive vascular lesions which severely reduce the quality of life. Pre-existing liver cirrhosis presents unique challenges during the surgical management of such lesions. We carried out a retrospective study of 42 patients who had been managed surgically for skeletal metastases from hepatocellular carcinoma affecting the appendicular skeleton between January 2000 and December 2006. There were 38 men and four women with a mean age of 60.2 years (46 to 77). Surgery for a pathological fracture was undertaken in 30 patients and because of a high risk of fracture in 12. An intralesional surgical margin was achieved in 36 and a wide margin in six. Factors influencing survival were determined by univariate and multivariate analyses. The survival rates at one, two and three years after surgery were 42.2%, 25.8% and 19.8%, respectively. The median survival time was ten months (95% confidence interval 6.29 to 13.71). The number of skeletal metastases and the Child-Pugh grade were identified as independent prognostic factors by Cox regression analysis. The method of management of the hepatocellular carcinoma, its status in the liver, the surgical margin for skeletal metastases, the presence of a pathological fracture and adjuvant radiotherapy were not found to be significantly related to the survival of the patient, which was affected by hepatic function, as represented by the Child-Pugh grade.

Reunion of the rabbit superior oblique tendon after weakening procedures

Purpose

To investigate the degree of reunion in rabbit eyes of the superior oblique tendon after several surgical weakening procedures.

Methods

A total of 32 rabbits (64 eyes) were used in this study. The rabbits were randomly assigned to four groups, eight rabbits (16 eyes) in the tenotomy group, eight rabbits (16 eyes) in the tenectomy group, eight rabbits (16 eyes) in the disinsertion group and eight rabbits (16 eyes) in the recession group. The degree of reunion or reattachment of the superior oblique tendon on the globe were examined on four eyes in each group at postoperative weeks two, four, six and eight.

Results

At eight weeks, the newly created insertion site remained at the same site in all eyes in the recession group, and the distal end of the superior oblique tendon was reattached at the medial border of the superior rectus muscle in all four eyes in the tenotomy and disinsertion groups, and in three of four eyes in the tenectomy group.

Conclusions

From this experimental study, it was speculated that superior oblique recession is more effective than other superior oblique weakening procedures. This result could be helpful in the prediction of time of recurrence for superior oblique overaction after superior oblique weakening procedures.

Computed tomographic assessment of reduction of the distal radioulnar joint by gradual lengthening of the radius

Congruency of the distal radioulnar joint was assessed by computed tomography after gradual lengthening of the radius in patients with considerable ulnar positive variance of mean 12 (range 10-17) mm and chronic dislocation of the distal radioulnar joint. Six patients of mean age 25 years were treated by radial osteotomy and subsequent gradual lengthening using either a single-rod or a half-ring external fixator, which was applied for a mean of 81 days. The causes of deformity were distal radial epiphyseal injury in four, malunion of a radius shaft fracture in one and Madelung deformity in one. Computed tomography scans taken at 1 year postoperatively demonstrated that all patients had a congruent distal radioulnar joint. All patients achieved symptom and radiographic parameter improvements at a mean follow-up of 40 months. A disadvantage was unattractive scars on a cosmetically important surface of the forearm. Given a relatively intact bony contour of the distal radioulnar joint, congruent reduction of the distal radioulnar joint can be obtained by gradual lengthening of the radius.