Humidity-tolerant porous polymer coating for passive daytime radiative cooling.

Coating building envelopes with a passive daytime radiative cooling (PDRC) material has attracted enormous attention as an alternative cooling technique with minimal energy consumption and carbon footprint. Despite the exceptional performance and scalability of porous polymer coating (PPC), achieving consistent performance over a wide range of drying environments remains a major challenge for its commercialization as a radiative cooling paint. Herein, we demonstrate the humidity vulnerability of PPC during the drying process and propose a simple strategy to greatly mitigate the issue. Specifically, we find that the solar reflectance of the PPC rapidly decreases with increasing humidity from 30% RH, and the PPC completely losses its PDRC ability at 45% RH and even become a solar-heating material at higher humidity. However, by adding a small amount of polymer reinforcement to the PPC, it maintains its PDRC performance up to 60% RH, resulting in a 950% increase in estimated areal coverage compared to PPC in the United States. This study sheds light on a crucial consistency issue that has thus far been rarely addressed, and offers engineering guidance to handle this fundamental threat to the development of dependable PDRC paint for industrial applications.

High refractive index metamaterials using corrugated metallic slots.

We report on a method for realizing high refractive index metamaterials using corrugated metallic slot structures at terahertz frequencies. The effective refractive index and peak index frequency can be controlled by varying the width of the air gap in the corrugated slot arrays. The phenomenon occurs because of the secondary resonance effect due to the fundamental inductive-capacitive resonance, which generates a red-shift of the fundamental resonance determined by twice the length of the corrugated metallic slots. In addition, multiple gaps in the corrugated slots act as plasmonic hotspots which have the properties of three-dimensional subwavelength confinement due to extremely strong enhancement of the terahertz waves. The versatile characteristics of the structures may have many potential applications in designing compact optical devices incorporating various functionalities and in developing highly sensitive spectroscopic/imaging systems.

Effect of physiological posterolateral rotatory laxity on early results of posterior cruciate ligament reconstruction with posterolateral corner reconstruction.

BACKGROUND: The purpose of this study was to evaluate the influence of physiological posterolateral rotatory laxity on posterior cruciate ligament (PCL) reconstruction in terms of posterior stability and clinical outcomes. METHODS: We retrospectively reviewed the records of sixty-five patients who had undergone arthroscopic PCL reconstruction with simultaneous reconstruction of the posterolateral corner from March 2004 to April 2009. Patients were categorized into three groups according to the amount of tibial external rotation at 90° of knee flexion on the uninjured side: Group 1 (<40°; n = 26), Group 2 (between 40° and 50°; n = 21), and Group 3 (>50°; n = 18). Knee instability was assessed with posterior and varus stress radiographs as well as with the dial test at 30° and 90° of knee flexion. Functional scores were assessed with use of the Lysholm score and the International Knee Documentation Committee (IKDC) score preoperatively and at the time of final follow-up. RESULTS: At the time of follow-up, there was no significant difference among the three groups with regard to the mean side-to-side difference in posterior translation as measured with Telos stress radiography (Group 1: 3.6 ± 1.3 mm, Group 2: 3.3 ± 1.6 mm, and Group 3: 4.3 ± 1.6 mm; p = 0.098). There was also no significant difference among the groups with respect to knee stability as assessed on the varus stress radiographs or with the dial test at 30° and 90° of flexion. Finally, there was no significant difference among the groups with respect to the Lysholm or IKDC functional scores. CONCLUSIONS: This study suggests that the instability of knees that have PCL and posterolateral corner injuries with physiological posterolateral rotatory laxity can be controlled successfully with PCL reconstruction and simultaneous reconstruction of the posterolateral corner. Physiological posterolateral rotatory laxity should not be considered a risk factor for abnormal knee laxity after PCL reconstruction with simultaneous reconstruction of the posterolateral corner.

Arthroscopic repair of concomitant type II SLAP lesions in large to massive rotator cuff tears: comparison with biceps tenotomy.

BACKGROUND: There are no studies examining superior labrum anterior and posterior (SLAP) repair combined with repair of large to massive rotator cuff tears, and it is unclear whether a combined SLAP repair would lead to better outcomes than biceps tenotomy. HYPOTHESIS: Tenotomy and rotator cuff repair would lead to better outcomes compared with those of combined SLAP and rotator cuff repair. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: Our study population consisted of 36 patients who had undergone either combined SLAP and rotator cuff repair (when the biceps was too healthy to cut; group R = 16 patients) or tenotomy and rotator cuff repair (when any fraying or partial tear existed in the biceps tendon; group T = 20 patients) for concomitant type II SLAP lesions and large to massive rotator cuff tears. The cuff repair was performed in a single row for both groups. Outcomes were assessed by comparing range of motion as well as Simple Shoulder Test (SST), American Shoulder and Elbow Surgeons (ASES), and University of California, Los Angeles (UCLA) scores between the 2 groups. RESULTS: At the 2-year follow-up, both groups demonstrated significant improvements in functional shoulder scores and range of motion. However, group T had better SST scores (group T, 9.3 ± 1.6; group R, 7.8 ± 1.9; P = .012), ASES scores (group T, 88.6 ± 8.9; group R, 80.4 ±8.9; P = .009), UCLA scores (group T, 29.6 ± 3.0; group R, 26.0 ± 4.2; P = .007), and forward flexion (group T, 145.9° ± 13.0°; group R, 132.5° ± 15.3°; P = .008). The mean tear size and the degree of preoperative muscle atrophy and fatty infiltration on magnetic resonance imaging were similar between the groups. CONCLUSION: For patients with concomitant type II SLAP lesions and large to massive rotator cuff tears, the outcomes of simultaneous arthroscopic SLAP and rotator cuff repair were inferior to those of arthroscopic biceps tenotomy and cuff repair in terms of functional shoulder scores and range of motion. Biceps tenotomy and rotator cuff repair may be a more reliable method to address concomitant type II SLAP lesions and large to massive rotator cuff tears in patients, although a randomized controlled trial is needed to confirm the results.

Arthroscopic partial repair of irreparable large to massive rotator cuff tears.

PURPOSE: The aim of this study was to evaluate the outcome of arthroscopic partial repair and margin convergence of irreparable large to massive rotator cuff tears. METHODS: Between January 2003 and July 2008, 27 patients who met the inclusion criteria underwent arthroscopic partial repair and margin convergence of irreparable large to massive rotator cuff tears. An irreparable tear was defined as a tear with a minimum anterior-to-posterior width of 3 cm or larger, where it was not feasible to completely cover the humeral head with the cuff at the time of surgery. RESULTS: The mean preoperative tear size was 42.1 ± 6.2 mm. The mean size of the postoperative residual defect in the repaired tendon along the medial margin of the greater tuberosity was 12.0 ± 5.5 mm. All shoulder scores showed improvement. The Simple Shoulder Test improved from 5.1 ± 1.2 to 8.8 ± 2.1 (P < .001), the Constant score from 43.6 ± 7.9 to 74.1 ± 10.6 (P < .001), and the University of California, Los Angeles score from 10.5 ± 3.0 to 25.9 ± 5.0 (P < .001). Both Constant and University of California, Los Angeles shoulder scores also showed an inverse correlation with defect size. We compared muscle strength between the affected and contralateral sides and found that the strength of the affected side was not restored to the same level as the contralateral side (P < .001). CONCLUSIONS: Arthroscopic partial repair and margin convergence showed satisfactory short-term outcomes in irreparable large to massive rotator cuff tears. Thus it is suggested that, even in a large to massive tear that appears irreparable, attempting to repair it as much as possible to possibly convert it into a functional rotator cuff tear by re-creating a balanced forced couple can be helpful in reducing pain, as well as improving functional outcomes. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Anatomical Reconstruction for Chronic Posterolateral Instability Combined with Posterior Cruciate Ligament Reconstruction: Surgical Technique.

INTRODUCTION: We present surgical techniques for the anatomical reconstruction of the popliteus tendon and the lateral collateral ligament (LCL) with use of a tibialis posterior allograft for posterolateral corner insufficiency combined with anterolateral transtibial single-bundle posterior cruciate ligament (PCL) reconstruction with use of an Achilles tendon-bone allograft with a one-incision technique. STEP 1 CREATE THE PORTALS: Use a parapatellar high anteromedial portal, a far anterolateral portal, and a high posteromedial portal. STEP 2 PREPARE THE TIBIAL TUNNEL AND FEMORAL SOCKET FOR THE PCL RECONSTRUCTION: To reduce the graft/socket divergence, (1) flex the knee >100°, (2) push the proximal part of the tibia backward as much as possible, and (3) introduce the cannulated headed reamer through the far anterolateral portal with a smooth plastic sheath and push up posteriorly to make contact with the lateral femoral condyle. STEP 3 PREPARE PASS AND FIX THE GRAFT FOR THE PCL RECONSTRUCTION: Tie a 9-mm EndoPearl device securely to the tip of the tendon to improve the fixation strength. STEP 4 MAKE THE SKIN INCISION AND DEVELOP THE SURGICAL PLANE FOR THE POSTEROLATERAL CORNER RECONSTRUCTION: Create a 7-mm fibular tunnel in a counterclockwise direction to avoid breaking the lateral cortex of the fibular tunnel or injuring the peroneal nerve. STEP 5 PREPARE PASS AND FIX THE GRAFT FOR THE POSTEROLATERAL CORNER RECONSTRUCTION: Change the patient's position to a lateral or semi-lateral decubitus position to prevent an inappropriate posterolateral corner reconstruction by the posterolateral corner of the knee sagging in the supine position due to gravity. STEP 6 POSTOPERATIVE REHABILITATION: Immobilize the knee in extension, with the proximal part of the tibia supported with cotton pads to prevent posterior drooping, which may lead to graft stretch or failure. RESULTS: We performed a two-year follow-up study comparing the procedures described here (Group A) with the same PCL reconstruction technique combined with a modified biceps rerouting tenodesis to address the posterolateral corner deficiency (Group B). WHAT TO WATCH FOR: IndicationsContraindicationsPitfalls & Challenges.

Minimally invasive repair of pectus excavatum: a novel morphology-tailored, patient-specific approach.

OBJECTIVE: Minimally invasive repair of pectus excavatum, introduced by Nuss in 1998, has undergone a serious learning curve because of a lack of understanding on morphologies and repair techniques. To summarize the current status of minimally invasive repair of pectus excavatum, we reviewed and appraised our 10-year experience with a novel approach, a morphology-tailored technique, including diverse bar shaping, bar fixation, and techniques for adults. METHODS: We analyzed the data of 1170 consecutive patients with pectus excavatum who underwent minimally invasive repair between August 1999 and September 2008. All pectus repairs were performed by the primary author (H.J.P.) with our modified technique. RESULTS: The mean age was 10.3 years (range, 16 months to 51 years). There were 331 adult patients (>15 years) (28.3%). A total of 576 patients (49.2%) had bar removal after a mean of 2.5 years (range, 10 days to 7 years). The asymmetry index change (1.10-1.02, P < .001) demonstrated post-repair symmetry. Complication rates decreased through the 3 time periods (1999-2002 [n = 335]; 2003-2005 [n = 441]; 2006-2008 [n = 394]) as follows: pneumothorax rate (7.5% vs 4.3% vs 0.8%; P < .001) and bar displacement rate (3.8% vs 2.3% vs 0.5%; P = .002). Reoperation rate also decreased (4.8% vs 2.5% vs 0.8%; P = .002). Satisfaction outcomes were excellent in 92.7%, good in 5.9%, and fair in 1.4% of patients. After bar removal, 3 patients (0.6%) had minor recurrences. CONCLUSION: Minimally invasive repair of pectus excavatum based on a novel morphology-tailored, patient-specific approach is effective for quality repair of the full spectrum of pectus excavatum, including asymmetry and adult patients. Continuous technical refinements have significantly decreased the complication rates and postoperative morbidity.

Formation of nanosized organic molecular crystals on engineered surfaces.

The pharmaceutical industry has great interest in organic molecular nanosized crystals because their enhanced solubility and dissolution rate can potentially enhance drug bioavailability. In this work, patterned engineered surfaces were used to crystallize glycine with a lateral dimension below 200 nm in a confined volume while controlling supersaturation. Bifunctional patterned surfaces with hydrophilic islands, as small as 500 nm, surrounded by hydrophobic regions were prepared using lithography and self assembled monolayers. Individual glycine crystals under 200 nm were formed from the confined solutions wetting each hydrophilic island, while supersaturation was controlled by slow antisolvent diffusion. Individual crystals were characterized with AFM and Raman spectroscopy and determined to be the metastable beta form. The solubility enhancement as a function of crystal size was measured, and the solubility of crystals with a radius of 100 nm or less was estimated.

Needlescopic lung biopsy for interstitial lung disease and indeterminate pulmonary nodules: a report on 65 cases.

BACKGROUND: We evaluated the feasibility and accuracy of a needlescopic procedure for lung biopsies in patients with interstitial lung disease or indeterminate pulmonary nodules. METHODS: Sixty-five patients (36 women; mean age, 51.3 +/- 15.6; range, 13 to 76 years) underwent a needlescopic procedure to obtain lung biopsy specimens. Forty had indeterminate pulmonary nodules, and 25 had interstitial lung disease. A 2-mm needlescope and a 2-mm MiniSite Endo Grasp (Covidien, Norwalk, CT) were inserted at the sixth intercostal space along the middle and the posterior axillary line, respectively. Biopsy specimens were obtained using endostaplers. RESULTS: The average number of biopsy specimens was 1.7 +/- 0.6 (range, 1 to 4). For 9 patients, a frozen specimen was sent twice to pathology. Complete resection was continued after intraoperative pathology confirmation in 13 patients (lobectomy, 7; segmentectomy, 3; mass removal, 1; metastasectomy, 2). The volume of lung tissue was 8.7 +/- 11.8 cm3 (range, 0.15 to 55.44 cm3). The operation time was 58.7 +/- 37.5 minutes (range, 15 to 160 minutes). The final pathologic results were confirmed in all patients. No thoracoscopic procedure was converted to an open thoracotomy. Three patients (4.3%) had prolonged air leakage (> 5 days), and the chest tube remained in the pleural space for 2.3 +/- 2.4 days (range, 1 to 8 days). CONCLUSIONS: Needlescopic operation for lung biopsies in patients with interstitial lung disease and indeterminate pulmonary nodules is a minimally invasive procedure that is safe and effective for obtaining a diagnosis in selected patients.

Extreme eccentric canal type pectus excavatum: morphological study and repair techniques.

OBJECTIVE: Extreme eccentric canal type pectus excavatum (Grand Canyon type, GC, Type 2A3), is a distinct morphological variation, characterized by an eccentric longitudinal canal. Due to the extent of depression and asymmetry, repair is often challenging with the minimally invasive technique. Following, we present its morphologic characteristics and evaluate repair techniques according to morphology type. METHODS: Extreme eccentric canal type pectus excavatum is an eccentric, long canal-like chest wall depression from the infra-clavicle to lower chest. Among 851 patients who underwent pectus excavatum repair from 1999 to 2007, 112 patients (13.2%) had the eccentric canal type. Morphologic type and repair techniques were evaluated; results were assessed by pectus indices (depression index (DI), asymmetry index (AI), and eccentricity index (EI)). RESULTS: Of the asymmetric cases, 31% (112/361) were the eccentric canal type. Female proportion (male to female ratio=2.3) was higher than in general pectus excavatum (4.1, p<0.05). Young female adults were more frequently affected (8/17, 47%, p<0.05). Repair techniques included asymmetric bar (n=97, 86.6%), seagull bar (n=53, 47.3%), crest compression (n=13, 11.6%), and parallel bar (n=79, 70.5 %) techniques. Pectus indices changes were: DI (pre 2.89 to post 1, p<0.01), AI (pre 1.11 to post 1.03, p<0.01), and EI (pre 1.69 to post 1, p<0.01). AI change represented asymmetric to symmetric correction. CONCLUSIONS: Extreme eccentric canal type pectus excavatum represents a distinctive morphology and requires special techniques for repair. Post-repair symmetry can be achieved by an asymmetric bar technique. Upper chest wall depression can be corrected by a parallel bar technique. Protruding ridge was relieved by a seagull bar or crest compression technique.

Mechanism of bar displacement and corresponding bar fixation techniques in minimally invasive repair of pectus excavatum.

PURPOSE: Bar displacement is a major complication in repair of pectus excavatum with the Nuss technique. Mechanisms of bar displacement have been elucidated by case-by-case analysis, and specific bar fixation techniques have been developed to deal with each mechanism. The efficacy of our bar fixation techniques is appraised. METHODS: Data from 725 consecutive patients between 1999 and 2006 who were repaired with our modifications to the Nuss procedure were retrospectively analyzed. RESULTS: The mechanism of bar displacement consisted of one or a combination of the following types: type 1, "bar flipping"--rotation of the bar along the axis of hinge; type 2, "lateral sliding"--horizontal slipping of the bar to one side in asymmetric pectus excavatum; and type 3, "hinge-point disruption"--a dorsal shift of the bar owing to tearing of the supporting intercostal musculature. Specific bar fixation techniques have been tailored to compensate for potential mechanisms of bar displacement according to pectus morphology: multipoint pericostal bar fixation (MPF) (n = 496) for type 1 displacement; incorporation of a stabilizer on the depressed side (n = 169) for type 2 displacement; and hinge point reinforcement and the crane technique (n = 122) for type 3 displacement. The bar displacement rate was decreased with our mechanism-based approach (4.6% before MPF vs 1.8% after MPF, P = .045). In addition, the major complication rates (6.8% before MPF vs 2.0% after MPF, P = .001) and reoperation rates (5.5% before MPF vs 1.6% after MPF, P = .019) decreased. CONCLUSIONS: Mechanism-based bar fixation techniques, especially multipoint pericostal wire fixation, seems to be effective in preventing bar displacement following pectus excavatum repair.

Concomitant polymorphism in confined environment.

PURPOSE: The aim of this paper is to demonstrate that multiple crystal forms can be generated on patterned self-assembled monolayers (SAMs) substrates in single experiments in a given solvent system. METHODS: Functionalized metallic islands are fabricated and utilized as individual templates for crystal formation. Taking advantage of the different wetting properties that patterned surfaces offered, arrays of small solution droplets on the nano- and pico- liter scale were produced on the substrates. Different droplet dimensions were deposited on the substrate. As the solvent evaporates from the droplets, crystals were formed within the constrained volume. Crystal habits were examined with optical microscopy while the solid form was identified with Raman microscopy. RESULTS: With mefenamic acid (MA) and sulfathiazole as model pharmaceutical compounds, two and four different polymorphs, respectively, were observed under identical conditions. Moreover, it is established that the polymorphic distribution is highly dependent on the solvent evaporation rate and the solution concentration. These results imply that multiple crystal forms competitively nucleate in solution, and the probability of each form nucleating is strongly dependent on the supersaturation of the solution. Additionally, solvent was observed to play a role in controlling the solid state outcome. CONCLUSIONS: Multiple crystal forms can concomitantly nucleate on patterned substrates. This technique can particularly be attractive to screen for polymorphs as elusive, metastable solid forms are favored with the creation of high supersaturation and can be stabilized due to the minimal volumes generated.

Fibromuscular dysplasia of bilateral brachial arteries treated with surgery and consecutive thrombolytic therapy.

A 61-year-old female was admitted to our hospital complaining of paresthesia, pain, and intermittent weakness in the right hand. A pulsating mass with bruits had developed on the patient's upper arm. We also noted an absence of radial artery pulsation. The angiographic findings revealed a classic "string of beads" appearance, which involved both brachial and renal arteries. The right brachial artery exhibited an aneurysm, which was filled with thrombus, and the distal radial artery was occluded with thromboemboli. We excised the abnormal brachial artery segment, replacing it with an autogenous reversed saphenous vein conduit. Consecutive thrombolytic therapy was then performed for the treatment of the radial artery embolism. Histological examination revealed that the patient was suffering from medial fibromuscular dysplasia. This uncommon form of fibromuscular dysplasia, which involves both brachial arteries with embolization, can be efficiently treated via surgery and consecutive thrombolytic therapy.

Mid-term outcomes of side-to-side stapled anastomosis in cervical esophagogastrostomy.

This study was conducted to evaluate the mid-term results of cervical esophagogastric anastomosis using a side-to-side stapled anastomosis method for treatment of patients with malignant esophageal disease. A total of 13 patients were reviewed retrospectively from January 2001 to November 2005 who underwent total esophagectomy through a right thoracotomy, gastric tube formation through a midline laparotomy and finally a cervical esophagogastric anastomosis. Average patient age was 62.6 yr old and the male to female ratio was 11:2. The mean anastomosis time was measured to be about 32.5 min; all patients were followed for about 22.8+/-9.9 months postoperatively. There were no early or late mortalities. There were no complications of anastomosis site leakage or conduit necrosis. A mild anastomotic stricture was noted in one patient, and required two endoscopic bougination procedures at postoperative 4th month. Construction of a cervical esophagogastric anastomosis by side-to-side stapled anastomosis is relatively easy to apply and can be performed in a timely manner. Follow up outcomes are very good. We, therefore, suggest that the side-to-side stapled anastomosis could be used as a safe and effective option for cervical esophagogastric anastomosis.

Supradiaphragmatic bronchogenic cyst extending into the retroperitoneum.

We experienced a case of bronchogenic cyst located on the left lower pleural space extending into the retroperitoneum in a 33-year-old man with left chest pain. Preoperative imaging studies and operative findings showed a broad-based cystic mass on the left lower posterior pleura and diaphragmatic pleura extending into the retroperitoneal region across the diaphragm. Histologic studies proved this mass to be a bronchogenic cyst.

Crystallization on confined engineered surfaces: a method to control crystal size and generate different polymorphs.

Patterned glycine crystals nucleated on functionalized metallic square islands. This approach can be used to fabricate particles with micron dimensions and screen solid forms under different conditions. The size of the glycine crystals is controlled by the dimensions of the islands. High energy metastable beta-glycine crystallizes on small metallic islands, whereas for large islands, the polymorphic outcome becomes biased toward the alpha-form.

A simple technique for the thoracoscopic plication of the diaphragm.

We describe a simple technique for video-assisted thoracoscopic plication in patients with diaphragmatic eventration. During the plication, which is performed with a continuous running suture, a surgical assistant maintains the continuous suture traction using a homemade hook through the port. The technique can be performed easily, without any kind of thoracotomy.

Giant cell tumor originating from the anterior arc of the rib.

We report a case of giant cell tumor originating from the anterior arc of the rib. The tumor and the surrounding chest wall were completely resected, and the chest wall defect was covered with Marlex mesh. Giant cell tumor of the bone usually originates from the epiphysis of long bones. Even when the tumor occur in ribs, it usually occur in the posterior aspect. However, giant cell tumor should be included in the differential diagnosis of a tumor originating from the anterior arc of the ribs.