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Myxofibrosarcoma (MFS) is a rare and aggressive mesenchymal malignancy characterized by complex karyotypes with heterogeneous clinical features. The standard treatment for primary MFS is curative resection; however, the utility of systemic chemotherapy and radiotherapy has not been established. Although patient-derived cancer cell lines are a key bioresource for developing novel therapies, the number of MFS cell lines available from public cell banks is limited by the rarity of the disease, and large-scale drug screening has not yet been performed. To address this issue, we aimed to establish and characterize a novel MFS cell line. We successfully established a cell line, NCC-MFS6-C1, which harbors genetic abnormalities common in MFS and exhibits aggressive phenotypes such as continuous growth, spheroid formation, and invasion in tissue culture conditions. We performed drug screening using NCC-MFS6-C1 along with five MFS cell lines established in our laboratory and clarified the response spectrum of 214 existing anticancer agents. We found that two anticancer agents, gemcitabine and romidepsin, showed considerable antiproliferative effects, and these observations were concordant with the findings of our previous report, in which these agents attenuated the proliferation of five previously reported MFS cell lines. We conclude that NCC-MFS6-C1 is a useful resource for studying MFS.

Malignant rhabdoid tumor (MRT) is a sarcoma histologically characterized by rhabdoid cells and genetically characterized by loss of function of the chromatin remodeling complex SWI/SNF induced by SMARCB1 gene deficiency. MRT mainly occurs in children, may arise in various locations, but is predominantly in the central nervous system (CNS) and kidney. Although MRT exhibits poor prognosis, standard treatment has not yet been established due to its extreme rarity. Patient-derived cancer cell lines are critical tools for basic and pre-clinical research in the development of chemotherapy. However, none of the MRT cell lines was derived from adult patients, and only one cell line was derived from the MRT of a soft tissue, despite the clinical behavior of MRT varying according to patient age and anatomic site. Herein, we reported the first cell line of MRT isolated from the soft tissue of an adult patient and named it NCC-MRT1-C1. NCC-MRT1-C1 cells showed a biallelic loss of the SMARCB1 gene. NCC-MRT1-C1 cells demonstrated rapid proliferation, spheroid formation, invasion capability in vitro, and tumorigenesis in nude mice. Screening of antitumor agents in NCC-MRT1-C1 cells resulted in the identification of six effective drugs. In conclusion, we report the first MRT cell line from the soft tissue of an adult patient. We believe that NCC-MRT1-C1 is a useful tool for developing novel chemotherapies for MRT.

Synovial sarcoma (SS) is a rare and aggressive mesenchymal malignancy driven by a unique chromosomal translocation that generates the expression of the SS18:SSX fusion protein. It occurs at almost any anatomical site and most commonly in young adults. The standard curative treatment for primary SS is a wide surgical resection combined with radiotherapy and/or neoadjuvant chemotherapy. The prognosis of SS varies among patients, with the 5 years survival rate ranging from 50 to 60% in adults and 90% in children. Although patient-derived cell lines are a useful resource for the development of new therapies, only a few are available from public cell banks. Therefore, this study aimed to establish and characterize a novel SS cell line. We successfully established a novel cell line, NCC-SS5-C1, harboring an SS18-SSX1 fusion gene. NCC-SS5-C1 cells demonstrated constant growth and invasion ability. We performed integrative drug screening using eight SS cell lines, including NCC-SS5-C1 cells, and examined the response spectrum of existing anticancer agents. We conclude that NCC-SS5-C1 is a useful resource for studying SS.

Dedifferentiated liposarcoma (DDLPS) is morphologically characterized by well-differentiated liposarcomas associated with high-grade non-lipogenic sarcoma and molecularly characterized by the coamplification of MDM2 and CDK4(12q14-15). DDLPS is highly aggressive, and effective systemic chemotherapy has not been developed yet. In this study, we established a novel DDLPS cell line, NCC-DDLPS6-C1, as a potential tool for the development of novel therapies. NCC-DDLPS6-C1 cells were established from surgically resected tumor tissues of a patient with DDLPS. Amplification and overexpression of MDM2 and CDK4 were observed in NCC-DDLPS6-C1 cells. NCC-DDLPS6-C1 cells proliferated rapidly, invaded aggressively, and formed spheroids. Moreover, NCC-DDLPS6-C1 cells formed tumors in mice. These observations suggested that the malignant potentials that may reflect the original features of DDLPS were retained in the NCC-DDLPS6-C1. Anticancer drugs that significantly reduced the proliferation of NCC-DDLPS6-C1 cells were identified by drug library screening. Thus, NCC-DDLPS6-C1 may recapitulate the original genotypes and phenotypes, and we conclude that the NCC-DDLPS6-C1 cell line is a useful resource for the study of DDLPS.

Ewing sarcoma (ES) is a small round cell sarcoma that is characterized by the unique gene translocation EWSR1-FLI1. It is the second most common primary bone and soft tissue malignancy in children and adolescents. It constitutes 10-15% of all bone sarcomas and is highly aggressive and rapidly recurring. Although intensive treatments have improved the clinical outcome of ES patients, 20-25% of them exhibit metastases during diagnosis. Thus, the prognoses of these patients remain poor. Cell lines are pivotal resources to investigate the molecular background of disease progression and to develop novel therapeutic modalities. In this study, we established and characterized a novel ES cell line, NCC-ES2-C1. The presence of the EWSR1-FLI1 fusion gene in these cells was confirmed in the NCC-ES2-C1 cells. Furthermore, these cells exhibited constant proliferation, and invasion, but did not form tumors in mice. We screened the anti-tumor effects of 214 anti-cancer drugs in NCC-ES2-C1 cells and found that the drugs which effectively reduced the proliferation of NCC-ES2-C1 cells. We concluded that NCC-ES2-C1 cells are a useful resource to study functions of the EWSR1-FLI1 fusion gene, investigate phenotypic changes caused by genes and proteins, and evaluate the anti-tumor effects of novel drugs.

Malignant peripheral nerve sheath tumors (MPNSTs) are a rare subtype of mesenchymal tumors that arise from the sheath of peripheral nerves. MPNSTs exhibit strong metastatic potential, leading to poor clinical outcomes. The clinical utility of radiation therapy and chemotherapy is marginal with respect to overall survival and effective systematic therapies for MPNSTs are still needed to improve patient outcome. Although patient-derived cell lines are an essential tool for the development of novel therapies, only a limited number of cell lines have been reported and are available from cell banks. Thus, we established the novel MPNST cell line, NCC-MPNST6-C1, using surgically resected MPNST tissue. The NCC-MPNST6-C1 cells retained copy-number alterations similar to those of the original tumors and demonstrated constant proliferation, spheroid formation, and invasion capability in vitro, which reflected the malignant features of the original tumor tissue. While the NCC-MPNST6-C1 cells did not exhibit tumorigenesis in nude mice, their use in drug screening resulted in anti-cancer agents with low IC50 values. Hence, we conclude that the NCC-MPNST6-C1 cell line is a useful resource for the study of MPNSTs.

Pleomorphic liposarcoma (PLPS) is a highly malignant subtype of liposarcoma. It is histologically characterized by the presence of pleomorphic lipoblasts and can be accompanied by morphological foci that demonstrate differentiation to other histological lineages. PLPS is rare and accounts for only 5% of all liposarcomas. PLPS exhibits poor prognosis; distant metastases develop in 30-50% of patients after curative surgical resection, tumor-associated mortality occurs in up to 50% of patients, and effective chemotherapies for PLPS have not been established. The histological accompaniment of other morphological foci is an important prognostic factor for PLPS, and the development of chemotherapies for PLPS considering the histological morphology is necessary. Patient-derived cancer cell lines are critical tools for basic and pre-clinical research to understand diseases and develop chemotherapies. However, only two PLPS-derived cell lines have been reported, and their donor tumor specimens did not histologically accompany morphological foci other than lipoblasts. Thus, there is a need to establish patient-derived PLPS cell lines from various histological morphologies. Here, we report a novel PLPS cell line from a tumor specimen that histologically accompanied pleomorphic and bone-forming foci, and named it NCC-PLPS2-C1. NCC-PLPS2-C1 cells demonstrated constant proliferation, spheroid formation, and invasion capability in vitro. Screening of antitumor agents in NCC-PLPS2-C1 cells showed that bortezomib, romidepsin, and trabectedin were effective against NCC-PLPS2-C1. In conclusion, we report the first PLPS cell line from a tumor specimen that was morphologically accompanied by pleomorphic and born-forming foci. We believe that NCC-PLPS2-C1 will be useful for the development of novel chemotherapies for PLPS.

森田雅憲教授古稀祝賀記念号(Honorable issue in commemoration of Prof. Masanori Morita's 70 years of age)

Pleomorphic sarcoma (PS) is a heterogeneous group of malignant mesenchymal tumors without a specific histological lineage of differentiation. PS is genetically characterized by genetic instability and diversity and histologically characterized by morphological pleomorphism. PS is one of the most common soft tissue sarcomas. The only curative treatment for PS is complete surgical resection, in which neoadjuvant radiotherapy is frequently combined. PS demonstrates both local recurrence and metastasis after surgical treatment, and effective systemic chemotherapy has not yet been established. Patient-derived cancer cell lines are critical tools for basic and preclinical studies in the development of chemotherapy. However, only six PS cell lines are available from the public cell bank, and none of them are derived from PS after neoadjuvant radiotherapy, despite the fact that radiotherapy causes changes in the posttreatment cancer genome. Here, we reported a novel cell line of PS from a primary tumor specimen resected after neoadjuvant radiotherapy and named it NCC-PS1-C1. NCC-PS1-C1 cells showed a variety of copy number alterations and pathological mutations in TP53. NCC-PS1-C1 cells demonstrated constant proliferation, spheroid formation, and invasion capability in vitro. The screening of antitumor agents in NCC-PS1-C1 cells showed that bortezomib and romidepsin were effective against PS. In conclusion, we report a novel PS cell line from a primary tumor resected after neoadjuvant radiotherapy. We believe that NCC-PS1-C1 will be a useful tool for the development of novel chemotherapies for PS, especially for recurrent cases after neoadjuvant radiotherapy.

Giant cell tumor of bone (GCTB), is a rare intermediate malignant bone tumor with high local infiltrative ability, and is genetically characterized by mutation in the H3-3A gene. Standard treatment is curative surgical tumor resection. GCTB demonstrates both local recurrence and pulmonary metastasis after surgical treatment, and effective systematic chemotherapy is yet to be established. Therefore, development of novel chemotherapies for GCTB is necessary. Although patient-derived tumor cell lines are potent tools for preclinical research, 15 GCTB cell lines have been reported to date, and only four are publicly available. Thus, this study aimed to establish and characterize a novel GCTB cell line for preclinical studies on GCTB. Herein, we described the establishment of a cell line, NCC-GCTB5-C1, from the primary tumor tissue of a patient with GCTB. NCC-GCTB5-C1 was shown to harbor a mutation in the H3-3A gene, which is typical of GCTB; thus, it has useful properties for in vitro studies. We conducted the largest integrated screening analysis of 214 antitumor agents using NCC-GCTB5-C1 along with four GCTB cell lines. Romidepsin (a histone deacetylase inhibitor), camptothecin, and actinomycin D (topoisomerase inhibitors) demonstrated remarkable antitumor effects, suggesting that these antitumor agents are potential therapeutic candidates for GCTB treatment. Therefore, the NCC-GCTB5-C1 cell line could potentially contribute to the elucidation of GCTB pathogenesis and the development of novel GCTB treatments.

Myxoid liposarcoma (MLPS) is a lipogenic sarcoma, characterized by myxoid appearance histology and the presence of the FUS-DDIT3 fusion gene. MLPS shows frequent recurrence and poor prognosis after standard treatments, such as surgery. Therefore, novel therapeutic approaches for MLPS are needed. Development of novel treatments requires patient-derived cell lines to study the drug responses and their molecular backgrounds. Presently, only three cell lines of MLPS have been reported, and no line is available from public cell banks. Thus, this study aimed to establish and characterize novel MLPS cell lines. Using surgically resected tumor tissue from two patients with MLPS, two novel lines NCC-MLPS2-C1 and NCC-MLPS3-C1 were established. The presence of FUS-DDIT3 fusion, slow growth, spheroid formation, and invasive capability in these cell lines was confirmed. Growth retardation was monitored for 213 anti-cancer agents using NCC-MLPS2-C1 and NCC-MLPS3-C1 cells, and the results were integrated with the response to treatments in an MLPS cell line, NCC-MLPS1-C1, which was previously established in our laboratory. We found that romidepsin suppressed cell proliferation at considerably low concentrations in all three examined cell lines. NCC-MLPS2-C1 and NCC-MLPS3-C1 cell lines developed here represent a useful tool for basic and preclinical studies of MLPS.

Dedifferentiated liposarcoma (DDLPS) is a highly aggressive subtype of liposarcoma that is morphologically defined as a transition from a well-differentiated lipomatous component to a non-lipogenic one. Curative therapy for DDLPS is complete resection, and the benefits of current systemic chemotherapy remain marginal. Although DDLPS is molecularly characterized by co-amplification of MDM2 and CDK4 (12q14-15) and detailed genomic analyses have been conducted by multiple research groups, the effects of molecular targeted drugs are marginal, and novel therapeutic modalities are required. Although patient-derived cell lines are pivotal for cancer research, no DDLPS cell lines are currently available from public cell repositories. Accordingly, in this study, we established a novel DDLPS cell line, NCC-DDLPS5-C1, using surgically resected tumor tissues from a patient with DDLPS. NCC-DDLPS5-C1 cells exhibited typical gene amplification, overexpression of MDM2 and CDK4, and other DNA copy number alterations. The NCC-DDLPS5-C1 cells were capable of rapid cell proliferation, aggressive invasion, and spheroid formation, but not tumor formation in mice. We reported the utility of NCC-DDLPS5-C1 cells for a drug-response assay to detect anticancer drugs that significantly attenuated cell proliferation. Thus, we concluded that the NCC-DDLPS5-C1 cell line could be a useful resource for the study of DDLPS. Considering the diversity of disease in terms of clinical outcomes, continuous efforts are required to develop more patient-derived cancer models with different clinical and pathological backgrounds.

Li-Fraumeni syndrome (LFS) is a cancer predisposition syndrome caused by a germline mutation of the TP53. The lifetime risk of cancer in individuals with LFS is ≥ 70% for men and ≥ 90% for women. Undifferentiated pleomorphic sarcoma (UPS) is one of the core cancers associated with LFS. UPS is a subtype of undifferentiated soft tissue sarcoma that shows no identifiable line of differentiation. The standard curative treatment for UPS is complete surgical resection. However, local recurrence and distant metastasis to the lung can usually be found after resection of the UPS. Therefore, a novel treatment strategy for patients with UPS is required. Although well characterized, patient-derived tumor cell lines facilitate the high-throughput screening of a large number of drugs, and no sarcoma cell lines derived from a patient with LFS have been registered in public cell banks. Thus, this study aimed to establish a novel, well-characterized UPS cell line from a patient with LFS. From surgically resected UPS tumor tissues, we established the first UPS cell line from a patient with LFS and named it NCC-UPS4-C1. NCC-UPS4-C1 harbored copy number alterations and had the TP53 tumor suppressor gene mutation. The cells exhibited constant cell growth and invasive ability. This well-characterized NCC-UPS4-C1 cell line was then utilized for high-throughput screening of 214 anti-cancer drugs, and two effective drugs were identified. One of the two drugs, romidepsin, was commonly effective for the NCC-UPS1-C1, NCC-UPS2-C1, and NCC-UPS3-C1 cell lines that we previously reported; a potential drug for the treatment of UPS was suggested using well-characterized UPS cell lines. These data indicate that NCC-UPS4-C1, which is the first sarcoma cell line established from a patient with LFS, enables researchers to conduct vigorous preclinical research on UPS.

Malignant peripheral nerve sheath tumors (MPNSTs) are a rare subtype of mesenchymal tumors that arise from the sheath of peripheral nerves. MPNSTs exhibit strong metastatic potential, leading to poor clinical outcomes. The clinical utility of radiation therapy and chemotherapy is marginal with respect to overall survival and effective systematic therapies for MPNSTs are still needed to improve patient outcome. Although patient-derived cell lines are an essential tool for the development of novel therapies, only a limited number of cell lines have been reported and are available from cell banks. Thus, we established the novel MPNST cell line, NCC-MPNST6-C1, using surgically resected MPNST tissue. The NCC-MPNST6-C1 cells retained copy-number alterations similar to those of the original tumors and demonstrated constant proliferation, spheroid formation, and invasion capability in vitro, which reflected the malignant features of the original tumor tissue. While the NCC-MPNST6-C1 cells did not exhibit tumorigenesis in nude mice, their use in drug screening resulted in anti-cancer agents with low IC

Undifferentiated pleomorphic sarcoma (UPS), previously termed malignant fibrous histiocytoma, is one of the most aggressive sarcomas with no identifiable line of differentiation. Although the molecular mechanism of oncogenesis in UPS has not been clarified, radiation exposure is considered to be a risk factor in the development of UPS. In the treatment of UPS, surgical treatment remains the most important modality. While chemotherapy is considered in unresectable or metastatic cases, UPS is known to be refractory to conventional chemotherapy, leading to an unfavorable prognosis. To improve the clinical outcome of this condition, novel treatment methods are urgently needed. Patient-derived cell lines are essential tools in preclinical studies. However, owing to the rarity of UPS, only four UPS cell lines are publicly available. Thus, we established a novel UPS cell line, NCC-UPS3-C1, using a surgically resected tumor from a patient with radiation-associated UPS. NCC-UPS3-C1 cells had multiple genomic deletions including the tumor suppressor genes CDKN2A and CDKN2B. NCC-UPS3-C1 cells demonstrated constant growth, spheroid formation, and aggressive invasion ability. We also conducted a screening test using 214 drugs and identified that the histone deacetylase inhibitor, romidepsin, is highly effective on NCC-UPS3-C1 cells. Thus, we concluded that the NCC-UPS3-C1 cell line is a useful tool in preclinical studies for UPS.

Low production costs have contributed to the important role of lignite in the energy mixes of numerous countries worldwide. High moisture content, though, diminishes the applicability of lignite in power generation. Superheated steam drying is a prospective method of raising the calorific value of this fuel. This study describes the numerical model of superheated steam drying of lignite from the Belchatow mine in Poland in two aspects: single and multi-particle. The experimental investigation preceded the numerical analysis and provided the necessary data for the preparation and verification of the model. Spheres of 2.5 to 30 mm in diameter were exposed to the drying medium at the temperature range of 110 to 170 °C. The drying kinetics were described in the form of moisture content, drying rate and temperature profile curves against time. Basic coal properties, such as density or specific heat, as well as the mechanisms of heat and mass transfer in the particular stages of the process laid the foundations for the model construction. The model illustrated the drying behavior of a single particle in the entire range of steam temperature as well as the sample diameter. Furthermore, the numerical analyses of coal batches containing particles of various sizes were conducted to reflect the operating conditions of the dryer. They were followed by deliberation on the calorific value improvement achieved by drying, in terms of coal ingredients, power plant efficiency and dryer input composition. The initial period of drying was found crucial for upgrading the quality of coal. The accuracy of the model is capable of further improvement regarding the process parameters.

Dedifferentiated liposarcoma (DDLPS) is a highly malignant sarcoma characterized by the co-amplification of MDM2 and CDK4. Although systemic chemotherapy is recommended for unresectable or metastatic cases, DDLPS is insensitive to conventional chemotherapy, leading to an unfavorable prognosis. Therefore, novel treatment methods are urgently required. Patient-derived cell lines are essential in preclinical studies. Recently, large-scale screening studies using a number of cell lines have been actively conducted for the development of new therapeutic drugs. However, the DDLPS cell line cannot be obtained from public cell banks owing to its rarity, hindering screening studies. As such, novel DDLPS cell lines need to be established. Accordingly, this study aimed to establish a novel DDLPS cell line from surgical specimens. The cell line was named NCC-DDLPS4-C1. NCC-DDLPS4-C1 cells retained copy number alterations corresponding to the original tumors. Further, the cells demonstrated constant growth, spheroid formation, and equivalent invasiveness to MG63 osteosarcoma cells. We also conducted drug screening and integrated the results with those of the previously reported DDLPS cell lines. Consequently, we identified the histone deacetylase inhibitor romidepsin as a novel candidate drug. In conclusion, the NCC-DDLPS4-C1 cell line is a useful tool for the basic study of DDLPS.

Low calorific value of lignite, mostly attributed to high moisture content, undermines usability of this low rank coal. Upgrading the quality of this energy carrier, which benefits coal-fired power plant's thermal efficiency, can be effectively realized by means of drying. The kinetics of superheated steam drying was studied for 30 mm spherical samples from Belchatow lignite mine in Poland. The experiment featured simultaneous and continuous measurements of weight and temperature. The drying kinetics, described by curves of moisture content, drying rate and temperature profile, were evaluated using the data acquired. The appearance of the sample throughout the process was video-recorded. Widespread cracking and shrinkage, which differ depending on the conditions, along with series of droplets typical for larger sample, were observed. The examined particles were suitable for predictions of thermodynamically derived drying rate and time, as proposed in the previous study for 5 and 10 mm particles from the same coal deposit. However, in comparison they exhibited more uniform density distribution. On the basis of experimental results and material properties, the numerical model of drying process was applied. Simulated drying behavior was consistent with empirical observations. Extensive investigation, revealing features of variously-sized samples as well as diameter dependence on drying process, is required for purposes of designing industrial drying system dedicated to specific type of coal.

Summary Integrated coal Gasification Combined Cycle (IGCC) is the most advanced technology for coal-fired power generation. The two-stage entrained flow gasification process allows for the use of a wide range of coal, as long as the gasification temperature is above the ash melting point of a used fuel. In this gasification technology, lignite, which often has a low ash melting point, can be preferably utilized. However, ash fluidity is also another importance, because the behaviour of molten slag can diminish a stable ash discharge from a gasifier. As the eligibility of coal ash properties is a considerable factor, water physically and chemically kept in lignite (30 – 60% in mass) attributes to deteriorating gasification efficiency, because it causes significant heat loss and increasing oxygen consumption. Developing a thermal evaporative lignite drying method will be a necessary attempt to apply lignite to the coal gasification process. For those preceded objectives, coal and ash properties and drying characteristics of several grades of Polish lignite, extracted from Belchatow and Turow deposits, have been experimentally investigated in a preliminary study evaluating the applicability and consideration for its utilization in state-of-the-art clean coal technology, IGCC. This paper particularly discusses the eligibility of Polish lignite from the perspective of the fusibility and fluidity of ash melts and the fundamental drying kinetics of lignite in superheated steam in the light of water removal. The viscosity of ash melts is measured at high temperature up to 1700 °C. In the drying tests, the significant influence of structural issues, because of the provenance and origin of lignite on the drying characteristics, was found by applying the method of sensitivity analysis of physical propensity. This paper concludes that the investigated Polish lignite has characteristics favourable for utilization in IGCC technology, once the precautions related to its high moisture have been carefully addressed. Copyright © 2016 John Wiley & Sons, Ltd.

Lignite-fired coal power plants suffer from a significant heat loss due to the high moisture content in this energy carrier. Water removal from fuel is an indispensable treatment for improving the combustion process, which will foster the efficient utilization of lignite. Superheated steam fluidized bed drying is expected for this purpose in a power generation sector. Understanding drying kinetics of lignite will greatly reinforce design process of a dryer. Physical features as well as the drying behaviour may be divergent among the lignite originated from different depths and positions in a certain mine. To reveal and clarify the influence of the geological features, the drying characteristics of several grades of lignite from the Belchatow mine in Poland were investigated. The attempts to clarify the influence of the divergent properties of the investigated samples on the drying kinetics in superheated steam were presented in this paper.

A superheated steam fluidized bed dryer (SSFBD) in a self-heat recuperative configuration has a great potential of improving thermal efficiency of a lignite-fired power plant by recovering both of latent heat of vaporization of water kept in the fuel and part of sensible heat during the fuel processing. However, the optimal design of the dryer requires the fundamental knowledge of drying characteristics in respect to the individual properties of the utilized fuel. Experimental investigation to determine the correlation between a specific coal properties originated from geological background and its drying characteristics is thus the major concern in this paper. The investigated lignite is a representative of Turoszow deposit in Poland. Experimental attempts unveiling drying kinetics were carried out for 5 mm and 10 mm diameter spherical samples in the superheated steam atmosphere in the temperature range of 110 °C–170 °C. Simultaneous and continuous measurements of changes in weight, surface and interior temperatures and appearance on each tested sample were carried out for describing drying behavior. Analytical investigation was applied to explain the drying characteristics, which are strongly affected by the individual properties of coal and the inherent ash composition.

This paper investigates the private defense of intellectual properties in a standard North–South endogenous growth model in which R&D activities are endogenized. It identifies two major factors determining whether or not private defense activities contribute to economic growth: (i) The relative cost between private defense and innovation, and (ii) the strength of intellectual property laws in the South.

By incorporating endogenous selection of appropriability regimes into a North–South product-cycle model, this paper finds that there is an inverted U-shaped relationship between intellectual property rights protection in developing countries and innovation in developed countries.

Due to low production costs, lignite is an important component of energy mixes of countries in its possession. However, high moisture content undermines its applicability as fuel for power generation. Drying in superheated steam is a prospective method of upgrading quality of lignite. The study aimed to validate the drying model of lignite from Belchatow mine in Poland. The experimental investigation on superheated steam drying of lignite was previously conducted. Spheres of 10 mm in diameter were exposed to the drying medium at the temperature range of 110-170oC. The drying behaviour was described in the form of moisture content, drying rate and temperature profile curves against time. With the application of basic coal properties (e.g. density, water percentage, specific heat) as well as the mechanisms of heat and mass transfer in subsequent stages of the process, the numerical model of drying was constructed. It was tentatively verified with reference to experimental results both in terms of drying parameters and temperature. The model illustrated drying behaviour in the entire range of conditions. Nevertheless, further development of numerical model is desirable regarding accuracy of the process parameters.