Summary
We investigated the secular trends of the incidence and hospitalization cost of hip fracture in Tangshan, China. The incidence of hip fracture and the hospitalization cost were both ...increasing during the observation period.
Introduction
The present study aimed to determine sex-, age-, and fracture type-specific incidence and annual changes in hip fractures in Tangshan, China, between 2007 and 2018.
Methods
We analyzed annual hip fracture incidence using urban hospital data during 2007–2018 and calculated incidence rate/100,000 person years in each age group and sex. We assessed annual changes in incidence among people aged >60 years using linear-by-linear association tests and evaluated hospitalization costs with the Kruskal–Wallis test.
Results
During the study period, we observed an increasing proportion of hip fractures in people >60 years old from 14.2 to 22.79%. Crude hip fracture incidence increased markedly from 140.87 to 306.56/100,000 in women (
p
< 0.01) and from 124.83 to 167.19/100,000 in men (
p
< 0.01) in the age group >60 years. Type-specific analysis indicated significantly increased trends in incidence of cervical and trochanteric fractures among women and cervical fracture among men (
p
< 0.01). In people aged 36–60 years, the trend of hip fracture increased significantly in both sexes. The total and cervical-to-trochanteric ratio in men increased, with significant upward trends (
p
< 0.01). The proportion of cervical fracture was higher than that for trochanteric fracture in women, with stable levels from 2007 to 2018. Hospitalization costs for cervical and trochanteric fractures increased by 51.91% and 53.20%, respectively, during 2011–2018.
Conclusion
Tangshan will have an increasing burden on health care resources attributable to a considerable rise in hip fracture incidence and the older population. Further investigation of risk factors and subsequent implementation of effective measures to prevent hip fracture are needed.
► The latest developments in solar thermal applications are reviewed. ► Various types of solar collectors are summarised. ► Thermal energy storage approaches and systems are discussed. ► The current ...status of existing solar power stations is reviewed.
Thermal applications are drawing increasing attention in the solar energy research field, due to their high performance in energy storage density and energy conversion efficiency. In these applications, solar collectors and thermal energy storage systems are the two core components. This paper focuses on the latest developments and advances in solar thermal applications, providing a review of solar collectors and thermal energy storage systems. Various types of solar collectors are reviewed and discussed, including both non-concentrating collectors (low temperature applications) and concentrating collectors (high temperature applications). These are studied in terms of optical optimisation, heat loss reduction, heat recuperation enhancement and different sun-tracking mechanisms. Various types of thermal energy storage systems are also reviewed and discussed, including sensible heat storage, latent heat storage, chemical storage and cascaded storage. They are studied in terms of design criteria, material selection and different heat transfer enhancement technologies. Last but not least, existing and future solar power stations are overviewed.
Zhang R, Wang H, Tian Y‐Y, Yu X, Hu T, Dummer PMH. Use of cone‐beam computed tomography to evaluate root and canal morphology of mandibular molars in Chinese individuals. International Endodontic ...Journal, 44, 990–999, 2011.
Aim To evaluate the root canal configuration of permanent mandibular first and second molar teeth in a Chinese subpopulation using cone‐beam computed tomography (CBCT).
Methodology Patients who required CBCT radiographic examinations as part of their routine examination, diagnosis and treatment planning, were enrolled. Cases where the anatomy was compromised by physiological or pathological processes and the original root canal morphology was not clear were excluded. A total of 389 healthy, untreated, fully developed mandibular molars in Chinese individuals were included. The following observations were recorded: (i) the number of roots and their morphology; (ii) the number of canals per root; (iii) the canal configuration; (iv) the frequency of distolingual roots in the mandibular first molars and (v) the frequency of C‐shaped canals in the mandibular second molars. The root canal configurations were classified according to the method of Vertucci (Oral Surgery, Oral Medicine, and Oral Pathology58, 1984, 589).
Results The majority of mandibular molars (70% of first molars, 76% of second molars) had two separate roots; however, three roots were identified in 29% of first molars. C‐shaped roots occurred in 29% of second molars. Three canals were found in 56% of mandibular first molars and 43% had four canals. In the mandibular second molars, 46% had three canals and 38% had two canals. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal. There were seven variants of the root canal morphology amongst the mandibular first molars and eight variants amongst the mandibular second molars, without considering the various root types.
Conclusions Three‐rooted mandibular first molars and C‐shaped mandibular second molars occurred frequently in this Chinese population. CBCT is an effective tool for the detection of additional distolingual roots and C‐shaped roots/canals, and it is a valuable aid for dentists providing root canal treatment.
Intensity-modulated radiotherapy (IMRT) is the main salvage treatment for advanced locally recurrent nasopharyngeal carcinoma (NPC); however, survival outcomes vary. We aimed to construct a ...prognostic-score model to identify patients who could benefit from salvage IMRT.
This retrospective study involved 251 patients with locally recurrent NPC. The following parameters were analysed following IMRT: patient performance status, age, gender, late complications, T-stage of recurrence, synchronous nodal recurrence, primary gross tumour volume (GTV-nx), disease-free interval, re-irradiation dose and chemotherapy. The model was based on the hazard ratio coefficients of six significantly negative prognostic factors for survival.
Significantly negative prognostic factors included Karnofsky Performance Status ≤70, age >50 years, late complications, recurrent T(3-4) stage, synchronous nodal recurrence and GTV-nx >30 cm(3). Three subgroups were defined according to model scores: low risk (0-4), intermediate risk (5-8) and high risk (9-15). The 5-year overall survival rates were 64.3%, 32.2% and 7.7%, respectively. The main cause of death was radiation-induced complications.
The prognostic-score model demonstrated that re-irradiation with IMRT is suitable for low-risk and intermediate-risk patients but may be unsuitable for high-risk patients. Further research into the protection of critical adjacent organs to reduce late complications in these patients is warranted.
Tian Y.‐Y, Guo B, Zhang R, Yu X, Wang H, Hu T, Dummer PMH. Root and canal morphology of maxillary first premolars in a Chinese subpopulation evaluated using cone‐beam computed tomography. ...International Endodontic Journal., 45, 996–1003, 2012.
Aim To evaluate the external and internal anatomy of maxillary first premolar teeth in a Chinese subpopulation using cone‐beam computed tomography (CBCT).
Methodology A total of 300 CBCT images involving maxillary first premolar teeth were obtained from 241 patients who underwent CBCT scanning as part of an oral and dental examination for bone mass before placement of implants or to locate impacted teeth before orthodontic therapy. Tooth position, number of roots, canal configuration, number of canals and number of apical foramina per root were investigated. The Fisher’s exact test was used to analyse the correlation between root number and tooth position.
Results Overall, 66% (n = 198) of teeth had one root and 33% (n = 100) had two roots; the remaining 1% (n = 2) had three roots. This frequency distribution showed no statistical significance between left and right sides. The most frequent canal configuration of these maxillary first premolars was type IV (n = 153; 51%), followed by type II (n = 70; 23%), with only 1% (n = 2) of teeth having type VIII. One‐rooted teeth with canal bifurcations and/or combinations (types II, III, V, VI and VII) accounted for nearly 50% (n = 98) of the sample. Eighty‐five per cent (n = 255) of the teeth examined had two root canals (types II–VII), and 14% (n = 43) had one. Amongst the 59 patients with bilateral teeth, 38 had a symmetrical pattern of tooth anatomy, including the same number of roots and the same types of canal configurations.
Conclusions There was a high frequency of one‐rooted teeth amongst maxillary first premolars, with most having one root with two canals (types II–VII). The morphology of the canal in one‐rooted teeth was highly variable.
In the readout of silicon photomultipliers (SiPMs), the original current signals are usually divided into different channels — fast timing channels, slow energy channels, position encoding channels, ...facilitating the formation of different trigger types. This paper proposes a modified dynamic time over threshold (DTOT) method to obtain the energy information in the slow energy channel using the fast timing trigger of a 6 mm SiPM coupled to a 10 mm cubic GAGG scintillator. The dynamic threshold generator is triggered by a fast timing signal instead of the energy signal itself. The feasibility of this method was verified using a prototype circuit, wherein the integral nonlinearity was measured to be 1.5%. This method can easily introduce external triggers to the DTOT system, such as a coincident signal with a specific trigger logic, which can extend the application of the DTOT method.
The effects of metal foams on heat transfer enhancement in Phase Change Materials (PCMs) are investigated. The numerical investigation is based on the two-equation non-equilibrium heat transfer ...model, in which the coupled heat conduction and natural convection are considered at phase transition and liquid zones. The numerical results are validated by experimental data. The main findings of the investigation are that heat conduction rate is increased significantly by using metal foams, due to their high thermal conductivities, and that natural convection is suppressed owing to the large flow resistance in metal foams. In spite of this suppression caused by metal foams, the overall heat transfer performance is improved when metal foams are embedded into PCM; this implies that the enhancement of heat conduction offsets or exceeds the natural convection loss. The results indicate that for different metal foam samples, heat transfer rate can be further increased by using metal foams with smaller porosities and bigger pore densities.
► The effects of metal foams on heat transfer enhancement of thermal storage are investigated. ► The numerical investigation is based on the two-equation non-equilibrium heat transfer model. ► Heat can be transferred quickly through the foam structure to the whole domain of PCM. ► At the liquid zone, natural convection is suppressed by the metal foam structures, owing to the big flow resistance. ► Heat transfer rate can be further increased by using metal foams with smaller porosities and bigger pore densities.
Purpose: The performance of the Low-Profile Visualized Intraluminal Support (LVIS) stent deployed following balloon angioplasty is unknown in treating intracranial atherosclerotic stenosis, and this ...study was to investigate the safety and efficacy of the LVIS stent in treating intracranial atherosclerotic stenosis in the middle cerebral artery M1 segment. Methods: Thirty-five patients were enrolled with 35 atherosclerotic stenoses at the M1 segment. The stenosis was about 75% in 16 patients, 80% in 15, and 90% in the rest four. The LVIS stent was used to treat these patients. Results: The success rate of stenting was 97.1%. The stenting procedure was failed in one patient because of intraprocedural dissection of the stenotic (75%) segment, resulting in a 30-day periprocedural complication rate of 2.9% (1/35). Before stenting, the stenosis rate ranged 75%–90% (mean 78.9% ± 4.7%), and after stenting, the diameter of the stented segment was significantly (P < 0.0001) increased to 1.5–3.4 mm (mean 2.1 ± 0.32 mm) ranging 68.2%–100% (mean 94.0% ± 5.8%) of the normal arterial diameter, with the residual stenosis ranging 0–31.8% (median 4.8%, IQR 2.4%–7.3%). Follow-up was performed at 6–20 months (mean 8.5) after stenting. One patient (2.9%) had occlusion of the stented M1 segment with no symptoms, and two patients (5.7%) had slight asymptomatic instent stenosis (40%) at the M1 segment, with the instent restenosis and occlusion rate of 8.6% (3/35). Conclusion: The braided LVIS stent can be safely applied for treatment of intracranial atherosclerotic stenosis in the middle cerebral artery with good safety and efficacy immediately after stenting and at follow-up. Resumen: Objetivo: Nos propusimos analizar la seguridad y efectividad de la colocación de un stent low-profile visualized intraluminal support (LVIS™) tras angioplastia con balón en pacientes con estenosis ateroscleróticas intracraneales en el segmento M1 de la arteria cerebral media (ACM). Métodos: Incluimos 35 pacientes con estenosis ateroscleróticas en el segmento M1 de la ACM; la estenosis era del 75% en 16 pacientes, del 80% en 15 y del 90% en los 4 restantes. En todos los casos el tratamiento se basó en la colocación de un stent LVIS™. Resultados: El stent se implantó con éxito en el 97,1% de los casos; en un paciente, el procedimiento no se pudo llevar a cabo a causa de una disección del segmento estenótico (estenosis del 75%) durante la operación, lo que supone una tasa de complicaciones perioperatorias a los 30 días del 2,9%. Antes de la colocación del stent, el grado de estenosis oscilaba entre el 75 y el 90% (media DS: 78,9% 4,7%). Tras el procedimiento, el diámetro del segmento en el que se había colocado el stent aumentó de forma significativa (P < 0,0001) hasta los 1,5-3,4 mm (media: 2,1 mm 0,32), logrando un 68,2-100% (media: 94,0% 5,8%) del diámetro normal de la arteria, y una estenosis residual del 0 al 31,8% (mediana: 4,8%; p25-p75, 2,4-7,3%). Se realizó un seguimiento de entre 6 y 20 meses (media: 8,5) tras el procedimiento. Un paciente (2,9%) presentó una oclusión asintomática del segmento M1 intervenido, y 2 pacientes (5,7%) presentaron estenosis intrastent asintomáticas leves (40%) en M1, por lo que la tasa de reestenosis intrastent y oclusión fue del 8,6%. Conclusión: El stent LVIS™ es un tratamiento seguro y efectivo para las estenosis ateroscleróticas intracraneales en la ACM.
•The first review on Multiple Evaporators LHP (ME-LHP) developments for the past 20 years.•Three key design issues for a ME-LHP design are discussed.•The control rules of steady operation temperature ...in ME-LHP are reviewed.•Required superheat for ME-LHP start-up is analyzed.
Multi-evaporator loop heat pipe (ME-LHP), as one of the typical two-phase closed capillary circulation systems, exhibits tremendous potential in applications which involve high heat flux and multi-heat sources, and is especially attractive to spacecraft and electronics packaging thermal control. This paper provides a comprehensive review of ME-LHP research and developments for the past 20 years covering four aspects: design theory, mathematical models, steady-state operational performance and start-up performance. ME-LHP design theory contains three key problems including the number limit for evaporators, sizing of the compensation chamber (CC) and calculation of the working fluid charge. Three peculiar features in steady performance have been discussed, which are the heat load sharing feature, the control rules of the operation temperature among multiple CCs, and the capillary limit of ME-LHP. Two influencing factors of start-up performance have been taken into account, including the required superheat on ME-LHP start-up and the initial fluid distribution in evaporators.
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